661634650 has 24 divisors (see below), whose sum is σ = 1239636060. Its totient is φ = 262719360.

The previous prime is 661634647. The next prime is 661634653. The reversal of 661634650 is 56436166.

It is an interprime number because it is at equal distance from previous prime (661634647) and next prime (661634653).

It can be written as a sum of positive squares in 6 ways, for example, as 101223721 + 560410929 = 10061^2 + 23673^2 .

It is not an unprimeable number, because it can be changed into a prime (661634653) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41445 + ... + 55144.

Almost surely, 2^661634650 is an apocalyptic number.

661634650 is a deficient number, since it is larger than the sum of its proper divisors (578001410).

661634650 is a wasteful number, since it uses less digits than its factorization.

661634650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96738 (or 96733 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 37.

The square root of 661634650 is about 25722.2598151873. The cubic root of 661634650 is about 871.3769756759.

The spelling of 661634650 in words is "six hundred sixty-one million, six hundred thirty-four thousand, six hundred fifty".