21351654065 has 16 divisors (see below), whose sum is σ = 29584152192. Its totient is φ = 14490192384.

The previous prime is 21351654053. The next prime is 21351654113. The reversal of 21351654065 is 56045615312.

It is a cyclic number.

It is not a de Polignac number, because 21351654065 - 2²⁸ = 21083218609 is a prime.

It is a super-2 number, since 2×21351654065² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3141179 + ... + 3147968.

It is an arithmetic number, because the mean of its divisors is an integer number (1849009512).

Almost surely, 2^21351654065 is an apocalyptic number.

It is an amenable number.

21351654065 is a deficient number, since it is larger than the sum of its proper divisors (8232498127).

21351654065 is an equidigital number, since it uses as much as digits as its factorization.

21351654065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6289256.

The product of its (nonzero) digits is 108000, while the sum is 38.

The spelling of 21351654065 in words is "twenty-one billion, three hundred fifty-one million, six hundred fifty-four thousand, sixty-five".