661938770 has 32 divisors (see below), whose sum is σ = 1207260288. Its totient is φ = 261289728.

The previous prime is 661938757. The next prime is 661938773. The reversal of 661938770 is 77839166.

661938770 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×661938770² = 876325870458225800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (661938773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 346157 + ... + 348063.

It is an arithmetic number, because the mean of its divisors is an integer number (37726884).

Almost surely, 2^661938770 is an apocalyptic number.

661938770 is a deficient number, since it is larger than the sum of its proper divisors (545321518).

661938770 is a wasteful number, since it uses less digits than its factorization.

661938770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2354.

The product of its (nonzero) digits is 381024, while the sum is 47.

The square root of 661938770 is about 25728.1707472568. The cubic root of 661938770 is about 871.5104645399.

The spelling of 661938770 in words is "six hundred sixty-one million, nine hundred thirty-eight thousand, seven hundred seventy".