155560621761 has 24 divisors (see below), whose sum is σ = 230227181184. Its totient is φ = 101169842400.

The previous prime is 155560621691. The next prime is 155560621819. The reversal of 155560621761 is 167126065551.

It is a happy number.

155560621761 is a `hidden beast` number, since 1 + 5 + 5 + 560 + 6 + 21 + 7 + 61 = 666.

It is not a de Polignac number, because 155560621761 - 2⁷ = 155560621633 is a prime.

It is a super-2 number, since 2×155560621761² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (155560621661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 469090 + ... + 728811.

It is an arithmetic number, because the mean of its divisors is an integer number (9592799216).

Almost surely, 2^155560621761 is an apocalyptic number.

It is an amenable number.

155560621761 is a deficient number, since it is larger than the sum of its proper divisors (74666559423).

155560621761 is a wasteful number, since it uses less digits than its factorization.

155560621761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1198261 (or 1198258 counting only the distinct ones).

The product of its (nonzero) digits is 378000, while the sum is 45.

The spelling of 155560621761 in words is "one hundred fifty-five billion, five hundred sixty million, six hundred twenty-one thousand, seven hundred sixty-one".