20999549675520 has 1152 divisors, whose sum is σ = 80196399803520. Its totient is φ = 5050568540160.

The previous prime is 20999549675513. The next prime is 20999549675539. The reversal of 20999549675520 is 2557694599902.

20999549675520 is a `hidden beast` number, since 2 + 0 + 9 + 9 + 9 + 5 + 4 + 9 + 67 + 552 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10515547162 + ... + 10515549158.

It is an arithmetic number, because the mean of its divisors is an integer number (69614930385).

Almost surely, 2^{20999549675520} is an apocalyptic number.

20999549675520 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 20999549675520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40098199901760).

20999549675520 is an abundant number, since it is smaller than the sum of its proper divisors (59196850128000).

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

20999549675520 is a wasteful number, since it uses less digits than its factorization.

20999549675520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2241 (or 2218 counting only the distinct ones).

The product of its (nonzero) digits is 551124000, while the sum is 72.

The spelling of 20999549675520 in words is "twenty trillion, nine hundred ninety-nine billion, five hundred forty-nine million, six hundred seventy-five thousand, five hundred twenty".