661116061015 has 16 divisors (see below), whose sum is σ = 801728319168. Its totient is φ = 523303013376.

The previous prime is 661116060977. The next prime is 661116061033. The reversal of 661116061015 is 510160611166.

It is a cyclic number.

It is not a de Polignac number, because 661116061015 - 2¹³ = 661116052823 is a prime.

It is a super-2 number, since 2×661116061015² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1691814 + ... + 2045596.

It is an arithmetic number, because the mean of its divisors is an integer number (50108019948).

Almost surely, 2^661116061015 is an apocalyptic number.

661116061015 is a deficient number, since it is larger than the sum of its proper divisors (140612258153).

661116061015 is a wasteful number, since it uses less digits than its factorization.

661116061015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357738.

The product of its (nonzero) digits is 6480, while the sum is 34.

The spelling of 661116061015 in words is "six hundred sixty-one billion, one hundred sixteen million, sixty-one thousand, fifteen".