15161501015661 has 64 divisors (see below), whose sum is σ = 27405785272320. Its totient is φ = 7199665136640.

The previous prime is 15161501015627. The next prime is 15161501015693. The reversal of 15161501015661 is 16651010516151.

It is not a de Polignac number, because 15161501015661 - 2¹⁹ = 15161500491373 is a prime.

It is a super-2 number, since 2×15161501015661² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15161501011661) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 24199356 + ... + 24817973.

It is an arithmetic number, because the mean of its divisors is an integer number (428215394880).

Almost surely, 2^{15161501015661} is an apocalyptic number.

15161501015661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15161501015661 is a deficient number, since it is larger than the sum of its proper divisors (12244284256659).

15161501015661 is a wasteful number, since it uses less digits than its factorization.

15161501015661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49017466.

The product of its (nonzero) digits is 27000, while the sum is 39.

The spelling of 15161501015661 in words is "fifteen trillion, one hundred sixty-one billion, five hundred one million, fifteen thousand, six hundred sixty-one".