661583454436 has 24 divisors (see below), whose sum is σ = 1195299090944. Its totient is φ = 320072653440.

The previous prime is 661583454407. The next prime is 661583454449. The reversal of 661583454436 is 634454385166.

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, 427681 + ... + 1227223.

Almost surely, 2^661583454436 is an apocalyptic number.

It is an amenable number.

661583454436 is a deficient number, since it is larger than the sum of its proper divisors (533715636508).

661583454436 is a wasteful number, since it uses less digits than its factorization.

661583454436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806251 (or 806249 counting only the distinct ones).

The product of its digits is 24883200, while the sum is 55.

The spelling of 661583454436 in words is "six hundred sixty-one billion, five hundred eighty-three million, four hundred fifty-four thousand, four hundred thirty-six".