661693238 has 4 divisors (see below), whose sum is σ = 992539860. Its totient is φ = 330846618.

The previous prime is 661693229. The next prime is 661693247. The reversal of 661693238 is 832396166.

661693238 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (661693229) and next prime (661693247).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165423308 + ... + 165423311.

It is an arithmetic number, because the mean of its divisors is an integer number (248134965).

Almost surely, 2^661693238 is an apocalyptic number.

661693238 is a deficient number, since it is larger than the sum of its proper divisors (330846622).

661693238 is a wasteful number, since it uses less digits than its factorization.

661693238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330846621.

The product of its digits is 279936, while the sum is 44.

The square root of 661693238 is about 25723.3986479236. The cubic root of 661693238 is about 871.4026951710.

The spelling of 661693238 in words is "six hundred sixty-one million, six hundred ninety-three thousand, two hundred thirty-eight".