661304245 has 24 divisors (see below), whose sum is σ = 952915968. Its totient is φ = 438832800.

The previous prime is 661304239. The next prime is 661304251. The reversal of 661304245 is 542403166.

It is an interprime number because it is at equal distance from previous prime (661304239) and next prime (661304251).

It is not a de Polignac number, because 661304245 - 2⁵ = 661304213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35941 + ... + 51130.

It is an arithmetic number, because the mean of its divisors is an integer number (39704832).

Almost surely, 2^661304245 is an apocalyptic number.

It is an amenable number.

661304245 is a deficient number, since it is larger than the sum of its proper divisors (291611723).

661304245 is a wasteful number, since it uses less digits than its factorization.

661304245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87121 (or 87114 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 661304245 is about 25715.8364631602. The cubic root of 661304245 is about 871.2319030402.

The spelling of 661304245 in words is "six hundred sixty-one million, three hundred four thousand, two hundred forty-five".