20407292640 has 576 divisors, whose sum is σ = 82397952000. Its totient is φ = 4596673536.

The previous prime is 20407292611. The next prime is 20407292701. The reversal of 20407292640 is 4629270402.

20407292640 is a `hidden beast` number, since 2 + 0 + 4 + 0 + 7 + 2 + 9 + 2 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20407292595 and 20407292604.

It is a congruent number.

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, 39019419 + ... + 39019941.

It is an arithmetic number, because the mean of its divisors is an integer number (143052000).

Almost surely, 2^20407292640 is an apocalyptic number.

20407292640 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 20407292640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41198976000).

20407292640 is an abundant number, since it is smaller than the sum of its proper divisors (61990659360).

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

20407292640 is a wasteful number, since it uses less digits than its factorization.

20407292640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644 (or 619 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The spelling of 20407292640 in words is "twenty billion, four hundred seven million, two hundred ninety-two thousand, six hundred forty".