661562788 has 24 divisors (see below), whose sum is σ = 1196641152. Its totient is φ = 319835424.

The previous prime is 661562771. The next prime is 661562791. The reversal of 661562788 is 887265166.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5595 + ... + 36802.

It is an arithmetic number, because the mean of its divisors is an integer number (49860048).

Almost surely, 2^661562788 is an apocalyptic number.

It is an amenable number.

661562788 is a deficient number, since it is larger than the sum of its proper divisors (535078364).

661562788 is a wasteful number, since it uses less digits than its factorization.

661562788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42531 (or 42529 counting only the distinct ones).

The product of its digits is 967680, while the sum is 49.

The square root of 661562788 is about 25720.8628937678. The cubic root of 661562788 is about 871.3454269658.

The spelling of 661562788 in words is "six hundred sixty-one million, five hundred sixty-two thousand, seven hundred eighty-eight".