20561814282240 has 2688 divisors, whose sum is σ = 93310186475520. Its totient is φ = 4256818790400.

The previous prime is 20561814282239. The next prime is 20561814282241. The reversal of 20561814282240 is 4228241816502.

It is a happy number.

20561814282240 is a `hidden beast` number, since 2 + 0 + 5 + 6 + 181 + 428 + 2 + 2 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (20561814282239) and next prime (20561814282241).

It is a tau number, because it is divible by the number of its divisors (2688).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20561814282241) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 75873853305 + ... + 75873853575.

It is an arithmetic number, because the mean of its divisors is an integer number (34713611040).

Almost surely, 2^{20561814282240} is an apocalyptic number.

20561814282240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20561814282240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46655093237760).

20561814282240 is an abundant number, since it is smaller than the sum of its proper divisors (72748372193280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20561814282240 is an frugal number, since it uses more digits than its factorization.

20561814282240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352 (or 299 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The spelling of 20561814282240 in words is "twenty trillion, five hundred sixty-one billion, eight hundred fourteen million, two hundred eighty-two thousand, two hundred forty".