661560615 has 160 divisors (see below), whose sum is σ = 1338163200. Its totient is φ = 311351040.

The previous prime is 661560607. The next prime is 661560623. The reversal of 661560615 is 516065166.

It is an interprime number because it is at equal distance from previous prime (661560607) and next prime (661560623).

It is not a de Polignac number, because 661560615 - 2³ = 661560607 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 661560615.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 8374146 + ... + 8374224.

It is an arithmetic number, because the mean of its divisors is an integer number (8363520).

Almost surely, 2^661560615 is an apocalyptic number.

661560615 is an abundant number, since it is smaller than the sum of its proper divisors (676602585).

661560615 is a wasteful number, since it uses less digits than its factorization.

661560615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 661560615 is about 25720.8206517599. The cubic root of 661560615 is about 871.3444729441.

The spelling of 661560615 in words is "six hundred sixty-one million, five hundred sixty thousand, six hundred fifteen".