15661656016501 has 32 divisors (see below), whose sum is σ = 18031019587200. Its totient is φ = 13453773511680.

The previous prime is 15661656016469. The next prime is 15661656016543. The reversal of 15661656016501 is 10561065616651.

It is not a de Polignac number, because 15661656016501 - 2⁵ = 15661656016469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15661656016571) 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 31 ways as a sum of consecutive naturals, for example, 257186065 + ... + 257246953.

It is an arithmetic number, because the mean of its divisors is an integer number (563469362100).

Almost surely, 2^{15661656016501} is an apocalyptic number.

15661656016501 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15661656016501 is a deficient number, since it is larger than the sum of its proper divisors (2369363570699).

15661656016501 is a wasteful number, since it uses less digits than its factorization.

15661656016501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64069.

The product of its (nonzero) digits is 972000, while the sum is 49.

The spelling of 15661656016501 in words is "fifteen trillion, six hundred sixty-one billion, six hundred fifty-six million, sixteen thousand, five hundred one".