21256025802 has 32 divisors (see below), whose sum is σ = 46388548800. Its totient is φ = 6439585920.

The previous prime is 21256025731. The next prime is 21256025807. The reversal of 21256025802 is 20852065212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21256025807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 235324 + ... + 312872.

It is an arithmetic number, because the mean of its divisors is an integer number (1449642150).

Almost surely, 2^21256025802 is an apocalyptic number.

21256025802 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21256025802 is an abundant number, since it is smaller than the sum of its proper divisors (25132522998).

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

21256025802 is a wasteful number, since it uses less digits than its factorization.

21256025802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81718.

The product of its (nonzero) digits is 19200, while the sum is 33.

The spelling of 21256025802 in words is "twenty-one billion, two hundred fifty-six million, twenty-five thousand, eight hundred two".