20857374720 has 768 divisors, whose sum is σ = 91361088000. Its totient is φ = 4395368448.

The previous prime is 20857374683. The next prime is 20857374787. The reversal of 20857374720 is 2747375802.

20857374720 is a `hidden beast` number, since 2 + 0 + 8 + 573 + 7 + 4 + 72 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (768).

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

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, 25159266 + ... + 25160094.

It is an arithmetic number, because the mean of its divisors is an integer number (118959750).

Almost surely, 2^20857374720 is an apocalyptic number.

20857374720 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 20857374720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45680544000).

20857374720 is an abundant number, since it is smaller than the sum of its proper divisors (70503713280).

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

20857374720 is a wasteful number, since it uses less digits than its factorization.

20857374720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 885 (or 859 counting only the distinct ones).

The product of its (nonzero) digits is 658560, while the sum is 45.

The spelling of 20857374720 in words is "twenty billion, eight hundred fifty-seven million, three hundred seventy-four thousand, seven hundred twenty".