661560767 has 16 divisors (see below), whose sum is σ = 773928960. Its totient is φ = 553713408.

The previous prime is 661560743. The next prime is 661560769. The reversal of 661560767 is 767065166.

It is a cyclic number.

It is not a de Polignac number, because 661560767 - 2²⁸ = 393125311 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661560769) 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, 158159 + ... + 162287.

It is an arithmetic number, because the mean of its divisors is an integer number (48370560).

Almost surely, 2^661560767 is an apocalyptic number.

661560767 is a deficient number, since it is larger than the sum of its proper divisors (112368193).

661560767 is a wasteful number, since it uses less digits than its factorization.

661560767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4670.

The product of its (nonzero) digits is 317520, while the sum is 44.

The square root of 661560767 is about 25720.8236065644. The cubic root of 661560767 is about 871.3445396774.

The spelling of 661560767 in words is "six hundred sixty-one million, five hundred sixty thousand, seven hundred sixty-seven".