21308919910 has 16 divisors (see below), whose sum is σ = 38591372016. Its totient is φ = 8471275488.

The previous prime is 21308919899. The next prime is 21308919913. The reversal of 21308919910 is 1991980312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21308919913) 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, 6534849 + ... + 6538108.

It is an arithmetic number, because the mean of its divisors is an integer number (2411960751).

Almost surely, 2^21308919910 is an apocalyptic number.

21308919910 is a deficient number, since it is larger than the sum of its proper divisors (17282452106).

21308919910 is a wasteful number, since it uses less digits than its factorization.

21308919910 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13073127.

The product of its (nonzero) digits is 34992, while the sum is 43.

The spelling of 21308919910 in words is "twenty-one billion, three hundred eight million, nine hundred nineteen thousand, nine hundred ten".