661510517 has 8 divisors (see below), whose sum is σ = 696564960. Its totient is φ = 626479920.

The previous prime is 661510513. The next prime is 661510559. The reversal of 661510517 is 715015166.

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

It is a cyclic number.

It is not a de Polignac number, because 661510517 - 2² = 661510513 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661510513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94883 + ... + 101615.

It is an arithmetic number, because the mean of its divisors is an integer number (87070620).

Almost surely, 2^661510517 is an apocalyptic number.

It is an amenable number.

661510517 is a deficient number, since it is larger than the sum of its proper divisors (35054443).

661510517 is a wasteful number, since it uses less digits than its factorization.

661510517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11923.

The product of its (nonzero) digits is 6300, while the sum is 32.

The square root of 661510517 is about 25719.8467530427. The cubic root of 661510517 is about 871.3224776215.

The spelling of 661510517 in words is "six hundred sixty-one million, five hundred ten thousand, five hundred seventeen".