661913386 has 8 divisors (see below), whose sum is σ = 997244640. Its totient is φ = 329498508.

The previous prime is 661913359. The next prime is 661913407. The reversal of 661913386 is 683319166.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 728526 + ... + 729433.

It is an arithmetic number, because the mean of its divisors is an integer number (124655580).

Almost surely, 2^661913386 is an apocalyptic number.

661913386 is a deficient number, since it is larger than the sum of its proper divisors (335331254).

661913386 is a wasteful number, since it uses less digits than its factorization.

661913386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1458188.

The product of its digits is 139968, while the sum is 43.

The square root of 661913386 is about 25727.6774311246. The cubic root of 661913386 is about 871.4993241820.

The spelling of 661913386 in words is "six hundred sixty-one million, nine hundred thirteen thousand, three hundred eighty-six".