21351101564265 has 64 divisors (see below), whose sum is σ = 37500934625280. Its totient is φ = 10287188904960.

The previous prime is 21351101564257. The next prime is 21351101564269. The reversal of 21351101564265 is 56246510115312.

It is not a de Polignac number, because 21351101564265 - 2³ = 21351101564257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21351101564269) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 222454356 + ... + 222550314.

It is an arithmetic number, because the mean of its divisors is an integer number (585952103520).

Almost surely, 2^{21351101564265} is an apocalyptic number.

It is an amenable number.

21351101564265 is a deficient number, since it is larger than the sum of its proper divisors (16149833061015).

21351101564265 is a wasteful number, since it uses less digits than its factorization.

21351101564265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104414.

The product of its (nonzero) digits is 216000, while the sum is 42.

Adding to 21351101564265 its reverse (56246510115312), we get a palindrome (77597611679577).

The spelling of 21351101564265 in words is "twenty-one trillion, three hundred fifty-one billion, one hundred one million, five hundred sixty-four thousand, two hundred sixty-five".