661904683 has 4 divisors (see below), whose sum is σ = 722077848. Its totient is φ = 601731520.

The previous prime is 661904647. The next prime is 661904687. The reversal of 661904683 is 386409166.

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

It is a cyclic number.

It is not a de Polignac number, because 661904683 - 2¹⁷ = 661773611 is a prime.

It is a super-3 number, since 3×661904683³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661904687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30086566 + ... + 30086587.

It is an arithmetic number, because the mean of its divisors is an integer number (180519462).

Almost surely, 2^661904683 is an apocalyptic number.

661904683 is a deficient number, since it is larger than the sum of its proper divisors (60173165).

661904683 is a wasteful number, since it uses less digits than its factorization.

661904683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60173164.

The product of its (nonzero) digits is 186624, while the sum is 43.

The square root of 661904683 is about 25727.5082936533. The cubic root of 661904683 is about 871.4955046028.

The spelling of 661904683 in words is "six hundred sixty-one million, nine hundred four thousand, six hundred eighty-three".