20256751640 has 32 divisors (see below), whose sum is σ = 45585970560. Its totient is φ = 8101228800.

The previous prime is 20256751589. The next prime is 20256751649. The reversal of 20256751640 is 4615765202.

It is a junction number, because it is equal to n+sod(n) for n = 20256751594 and 20256751603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20256751649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 192185 + ... + 278295.

It is an arithmetic number, because the mean of its divisors is an integer number (1424561580).

Almost surely, 2^20256751640 is an apocalyptic number.

20256751640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20256751640 is an abundant number, since it is smaller than the sum of its proper divisors (25329218920).

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

20256751640 is a wasteful number, since it uses less digits than its factorization.

20256751640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92003 (or 91999 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 38.

The spelling of 20256751640 in words is "twenty billion, two hundred fifty-six million, seven hundred fifty-one thousand, six hundred forty".