661265365507 has 16 divisors (see below), whose sum is σ = 697257793440. Its totient is φ = 626234095872.

The previous prime is 661265365493. The next prime is 661265365511. The reversal of 661265365507 is 705563562166.

It is not a de Polignac number, because 661265365507 - 2¹⁹ = 661264841219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661265365517) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 277608 + ... + 1183045.

It is an arithmetic number, because the mean of its divisors is an integer number (43578612090).

Almost surely, 2^661265365507 is an apocalyptic number.

661265365507 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

661265365507 is a deficient number, since it is larger than the sum of its proper divisors (35992427933).

661265365507 is a wasteful number, since it uses less digits than its factorization.

661265365507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1460982.

The product of its (nonzero) digits is 6804000, while the sum is 52.

The spelling of 661265365507 in words is "six hundred sixty-one billion, two hundred sixty-five million, three hundred sixty-five thousand, five hundred seven".