21621543364610 has 128 divisors (see below), whose sum is σ = 46085462438400. Its totient is φ = 7149469409280.

The previous prime is 21621543364609. The next prime is 21621543364649. The reversal of 21621543364610 is 1646334512612.

It is a super-2 number, since 2×21621543364610² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2127471389 + ... + 2127481551.

It is an arithmetic number, because the mean of its divisors is an integer number (360042675300).

Almost surely, 2^{21621543364610} is an apocalyptic number.

21621543364610 is an abundant number, since it is smaller than the sum of its proper divisors (24463919073790).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21621543364610 is a wasteful number, since it uses less digits than its factorization.

21621543364610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18636.

The product of its (nonzero) digits is 622080, while the sum is 44.

The spelling of 21621543364610 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred forty-three million, three hundred sixty-four thousand, six hundred ten".