661260513 has 16 divisors (see below), whose sum is σ = 888585152. Its totient is φ = 437400000.

The previous prime is 661260469. The next prime is 661260517. The reversal of 661260513 is 315062166.

It is not a de Polignac number, because 661260513 - 2⁶ = 661260449 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661260517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 292638 + ... + 294888.

It is an arithmetic number, because the mean of its divisors is an integer number (55536572).

Almost surely, 2^661260513 is an apocalyptic number.

It is an amenable number.

661260513 is a deficient number, since it is larger than the sum of its proper divisors (227324639).

661260513 is a wasteful number, since it uses less digits than its factorization.

661260513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2976.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 661260513 is about 25714.9861559364. The cubic root of 661260513 is about 871.2126977834.

The spelling of 661260513 in words is "six hundred sixty-one million, two hundred sixty thousand, five hundred thirteen".