661066715 has 16 divisors (see below), whose sum is σ = 843311520. Its totient is φ = 496051200.

The previous prime is 661066691. The next prime is 661066727. The reversal of 661066715 is 517660166.

It is not a de Polignac number, because 661066715 - 2⁸ = 661066459 is a prime.

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, 24854 + ... + 44043.

It is an arithmetic number, because the mean of its divisors is an integer number (52706970).

Almost surely, 2^661066715 is an apocalyptic number.

661066715 is a deficient number, since it is larger than the sum of its proper divisors (182244805).

661066715 is a wasteful number, since it uses less digits than its factorization.

661066715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69022.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 661066715 is about 25711.2176880054. The cubic root of 661066715 is about 871.1275796533.

The spelling of 661066715 in words is "six hundred sixty-one million, sixty-six thousand, seven hundred fifteen".