661956238 has 16 divisors (see below), whose sum is σ = 1090638720. Its totient is φ = 299924856.

The previous prime is 661956221. The next prime is 661956259. The reversal of 661956238 is 832659166.

It is a super-2 number, since 2×661956238² = 876372122054225288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

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, 377820 + ... + 379567.

It is an arithmetic number, because the mean of its divisors is an integer number (68164920).

Almost surely, 2^661956238 is an apocalyptic number.

661956238 is a deficient number, since it is larger than the sum of its proper divisors (428682482).

661956238 is a wasteful number, since it uses less digits than its factorization.

661956238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757431.

The product of its digits is 466560, while the sum is 46.

The square root of 661956238 is about 25728.5102172668. The cubic root of 661956238 is about 871.5181306119.

The spelling of 661956238 in words is "six hundred sixty-one million, nine hundred fifty-six thousand, two hundred thirty-eight".