641786815155 has 32 divisors (see below), whose sum is σ = 1053205312320. Its totient is φ = 333524817920.

The previous prime is 641786815147. The next prime is 641786815171. The reversal of 641786815155 is 551518687146.

It is not a de Polignac number, because 641786815155 - 2³ = 641786815147 is a prime.

It is a super-2 number, since 2×641786815155² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 641786815095 and 641786815104.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 147432 + ... + 1142501.

It is an arithmetic number, because the mean of its divisors is an integer number (32912666010).

Almost surely, 2^641786815155 is an apocalyptic number.

641786815155 is a deficient number, since it is larger than the sum of its proper divisors (411418497165).

641786815155 is a wasteful number, since it uses less digits than its factorization.

641786815155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1290791.

The product of its digits is 8064000, while the sum is 57.

The spelling of 641786815155 in words is "six hundred forty-one billion, seven hundred eighty-six million, eight hundred fifteen thousand, one hundred fifty-five".