661392628 has 12 divisors (see below), whose sum is σ = 1246470820. Its totient is φ = 305258112.

The previous prime is 661392617. The next prime is 661392637. The reversal of 661392628 is 826293166.

661392628 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 380562064 + 280830564 = 19508^2 + 16758^2 .

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6359493 + ... + 6359596.

Almost surely, 2^661392628 is an apocalyptic number.

It is an amenable number.

661392628 is a deficient number, since it is larger than the sum of its proper divisors (585078192).

661392628 is a wasteful number, since it uses less digits than its factorization.

661392628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12719106 (or 12719104 counting only the distinct ones).

The product of its digits is 186624, while the sum is 43.

The square root of 661392628 is about 25717.5548604450. The cubic root of 661392628 is about 871.2707145553.

The spelling of 661392628 in words is "six hundred sixty-one million, three hundred ninety-two thousand, six hundred twenty-eight".