661385172270 has 32 divisors (see below), whose sum is σ = 1591745955840. Its totient is φ = 175878096800.

The previous prime is 661385172223. The next prime is 661385172281. The reversal of 661385172270 is 72271583166.

It is a Curzon 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, 30694206 + ... + 30715745.

It is an arithmetic number, because the mean of its divisors is an integer number (49742061120).

Almost surely, 2^661385172270 is an apocalyptic number.

661385172270 is an abundant number, since it is smaller than the sum of its proper divisors (930360783570).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661385172270 is a wasteful number, since it uses less digits than its factorization.

661385172270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61410320.

The product of its (nonzero) digits is 846720, while the sum is 48.

The spelling of 661385172270 in words is "six hundred sixty-one billion, three hundred eighty-five million, one hundred seventy-two thousand, two hundred seventy".