21256313102 has 4 divisors (see below), whose sum is σ = 31884469656. Its totient is φ = 10628156550.

The previous prime is 21256313093. The next prime is 21256313119. The reversal of 21256313102 is 20131365212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5314078274 + ... + 5314078277.

It is an arithmetic number, because the mean of its divisors is an integer number (7971117414).

Almost surely, 2^21256313102 is an apocalyptic number.

21256313102 is a deficient number, since it is larger than the sum of its proper divisors (10628156554).

21256313102 is a wasteful number, since it uses less digits than its factorization.

21256313102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10628156553.

The product of its (nonzero) digits is 2160, while the sum is 26.

Adding to 21256313102 its reverse (20131365212), we get a palindrome (41387678314).

The spelling of 21256313102 in words is "twenty-one billion, two hundred fifty-six million, three hundred thirteen thousand, one hundred two".