20256603978 has 96 divisors (see below), whose sum is σ = 46251343872. Its totient is φ = 5902977600.

The previous prime is 20256603977. The next prime is 20256604001. The reversal of 20256603978 is 87930665202.

It is not an unprimeable number, because it can be changed into a prime (20256603977) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1470543 + ... + 1484253.

It is an arithmetic number, because the mean of its divisors is an integer number (481784832).

Almost surely, 2^20256603978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20256603978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23125671936).

20256603978 is an abundant number, since it is smaller than the sum of its proper divisors (25994739894).

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

20256603978 is a wasteful number, since it uses less digits than its factorization.

20256603978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13820 (or 13807 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 48.

The spelling of 20256603978 in words is "twenty billion, two hundred fifty-six million, six hundred three thousand, nine hundred seventy-eight".