21621451514465 has 16 divisors (see below), whose sum is σ = 29069430638400. Its totient is φ = 15299700333120.

The previous prime is 21621451514461. The next prime is 21621451514473. The reversal of 21621451514465 is 56441515412612.

It is not a de Polignac number, because 21621451514465 - 2² = 21621451514461 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21621451514461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5312393915 + ... + 5312397984.

It is an arithmetic number, because the mean of its divisors is an integer number (1816839414900).

Almost surely, 2^{21621451514465} is an apocalyptic number.

It is an amenable number.

21621451514465 is a deficient number, since it is larger than the sum of its proper divisors (7447979123935).

21621451514465 is a wasteful number, since it uses less digits than its factorization.

21621451514465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10624791952.

The product of its digits is 1152000, while the sum is 47.

The spelling of 21621451514465 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred fifty-one million, five hundred fourteen thousand, four hundred sixty-five".