661560501 has 8 divisors (see below), whose sum is σ = 1008092224. Its totient is φ = 378034560.

The previous prime is 661560443. The next prime is 661560509. The reversal of 661560501 is 105065166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661560501 - 2⁶ = 661560437 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661560509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15751420 + ... + 15751461.

It is an arithmetic number, because the mean of its divisors is an integer number (126011528).

Almost surely, 2^661560501 is an apocalyptic number.

It is an amenable number.

661560501 is a deficient number, since it is larger than the sum of its proper divisors (346531723).

661560501 is a wasteful number, since it uses less digits than its factorization.

661560501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31502891.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 661560501 is about 25720.8184356564. The cubic root of 661560501 is about 871.3444228941.

The spelling of 661560501 in words is "six hundred sixty-one million, five hundred sixty thousand, five hundred one".