21387016610 has 16 divisors (see below), whose sum is σ = 38503800576. Its totient is φ = 8553213168.

The previous prime is 21387016603. The next prime is 21387016621. The reversal of 21387016610 is 1661078312.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 142034 + ... + 250893.

It is an arithmetic number, because the mean of its divisors is an integer number (2406487536).

Almost surely, 2^21387016610 is an apocalyptic number.

21387016610 is a deficient number, since it is larger than the sum of its proper divisors (17116783966).

21387016610 is a wasteful number, since it uses less digits than its factorization.

21387016610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398377.

The product of its (nonzero) digits is 12096, while the sum is 35.

The spelling of 21387016610 in words is "twenty-one billion, three hundred eighty-seven million, sixteen thousand, six hundred ten".