156555616661 has 4 divisors (see below), whose sum is σ = 156569304672. Its totient is φ = 156541928652.

The previous prime is 156555616639. The next prime is 156555616687. The reversal of 156555616661 is 166616555651.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 156555616661 - 2¹⁴ = 156555600277 is a prime.

It is a super-2 number, since 2×156555616661² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156555616601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6826835 + ... + 6849728.

It is an arithmetic number, because the mean of its divisors is an integer number (39142326168).

Almost surely, 2^156555616661 is an apocalyptic number.

It is an amenable number.

156555616661 is a deficient number, since it is larger than the sum of its proper divisors (13688011).

156555616661 is a wasteful number, since it uses less digits than its factorization.

156555616661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13688010.

The product of its digits is 4860000, while the sum is 53.

The spelling of 156555616661 in words is "one hundred fifty-six billion, five hundred fifty-five million, six hundred sixteen thousand, six hundred sixty-one".