661267611672 has 32 divisors (see below), whose sum is σ = 1653262771200. Its totient is φ = 220410038304.

The previous prime is 661267611661. The next prime is 661267611679. The reversal of 661267611672 is 276116762166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661267611679) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 344128 + ... + 1200399.

It is an arithmetic number, because the mean of its divisors is an integer number (51664461600).

Almost surely, 2^661267611672 is an apocalyptic number.

It is an amenable number.

661267611672 is an abundant number, since it is smaller than the sum of its proper divisors (991995159528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661267611672 is a wasteful number, since it uses less digits than its factorization.

661267611672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1562375 (or 1562371 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 51.

The spelling of 661267611672 in words is "six hundred sixty-one billion, two hundred sixty-seven million, six hundred eleven thousand, six hundred seventy-two".