20516660115621 has 16 divisors (see below), whose sum is σ = 27377135425728. Its totient is φ = 13666979779200.

The previous prime is 20516660115593. The next prime is 20516660115643. The reversal of 20516660115621 is 12651106661502.

It is not a de Polignac number, because 20516660115621 - 2²¹ = 20516658018469 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20516660115661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 163930350 + ... + 164055456.

It is an arithmetic number, because the mean of its divisors is an integer number (1711070964108).

Almost surely, 2^{20516660115621} is an apocalyptic number.

It is an amenable number.

20516660115621 is a deficient number, since it is larger than the sum of its proper divisors (6860475310107).

20516660115621 is a wasteful number, since it uses less digits than its factorization.

20516660115621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167812.

The product of its (nonzero) digits is 129600, while the sum is 42.

The spelling of 20516660115621 in words is "twenty trillion, five hundred sixteen billion, six hundred sixty million, one hundred fifteen thousand, six hundred twenty-one".