661890630 has 32 divisors (see below), whose sum is σ = 1589612544. Its totient is φ = 176384736.

The previous prime is 661890629. The next prime is 661890653. The reversal of 661890630 is 36098166.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43257 + ... + 56523.

It is an arithmetic number, because the mean of its divisors is an integer number (49675392).

Almost surely, 2^661890630 is an apocalyptic number.

661890630 is an abundant number, since it is smaller than the sum of its proper divisors (927721914).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661890630 is a wasteful number, since it uses less digits than its factorization.

661890630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14940.

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 661890630 is about 25727.2351798634. The cubic root of 661890630 is about 871.4893369408.

The spelling of 661890630 in words is "six hundred sixty-one million, eight hundred ninety thousand, six hundred thirty".