20649727440 has 320 divisors, whose sum is σ = 77290291200. Its totient is φ = 5048179200.

The previous prime is 20649727393. The next prime is 20649727481. The reversal of 20649727440 is 4472794602.

It is a super-2 number, since 2×20649727440² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1264125 + ... + 1280355.

It is an arithmetic number, because the mean of its divisors is an integer number (241532160).

Almost surely, 2^20649727440 is an apocalyptic number.

20649727440 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 20649727440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38645145600).

20649727440 is an abundant number, since it is smaller than the sum of its proper divisors (56640563760).

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

20649727440 is a wasteful number, since it uses less digits than its factorization.

20649727440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16303 (or 16291 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 45.

The spelling of 20649727440 in words is "twenty billion, six hundred forty-nine million, seven hundred twenty-seven thousand, four hundred forty".