661261504 has 14 divisors (see below), whose sum is σ = 1312190924. Its totient is φ = 330630720.

The previous prime is 661261501. The next prime is 661261507. The reversal of 661261504 is 405162166.

It is an interprime number because it is at equal distance from previous prime (661261501) and next prime (661261507).

It is not an unprimeable number, because it can be changed into a prime (661261501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5166042 + ... + 5166169.

Almost surely, 2^661261504 is an apocalyptic number.

661261504 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

661261504 is a deficient number, since it is larger than the sum of its proper divisors (650929420).

661261504 is a wasteful number, since it uses less digits than its factorization.

661261504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10332223 (or 10332213 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 661261504 is about 25715.0054248487. The cubic root of 661261504 is about 871.2131329984.

The spelling of 661261504 in words is "six hundred sixty-one million, two hundred sixty-one thousand, five hundred four".