661406422228 has 12 divisors (see below), whose sum is σ = 1159780804000. Its totient is φ = 330040478232.

The previous prime is 661406422211. The next prime is 661406422249. The reversal of 661406422228 is 822224604166.

It is a congruent number.

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, 165680976 + ... + 165684967.

Almost surely, 2^661406422228 is an apocalyptic number.

It is an amenable number.

661406422228 is a deficient number, since it is larger than the sum of its proper divisors (498374381772).

661406422228 is a wasteful number, since it uses less digits than its factorization.

661406422228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331366446 (or 331366444 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 43.

The spelling of 661406422228 in words is "six hundred sixty-one billion, four hundred six million, four hundred twenty-two thousand, two hundred twenty-eight".