21655415666130 has 256 divisors, whose sum is σ = 56645107384320. Its totient is φ = 5279651186688.

The previous prime is 21655415666123. The next prime is 21655415666141. The reversal of 21655415666130 is 3166651455612.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4527577719 + ... + 4527582501.

It is an arithmetic number, because the mean of its divisors is an integer number (221269950720).

Almost surely, 2^{21655415666130} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21655415666130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28322553692160).

21655415666130 is an abundant number, since it is smaller than the sum of its proper divisors (34989691718190).

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

21655415666130 is a wasteful number, since it uses less digits than its factorization.

21655415666130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6553.

The product of its (nonzero) digits is 3888000, while the sum is 51.

The spelling of 21655415666130 in words is "twenty-one trillion, six hundred fifty-five billion, four hundred fifteen million, six hundred sixty-six thousand, one hundred thirty".