691651688772 has 48 divisors (see below), whose sum is σ = 1782853632000. Its totient is φ = 206938361760.

The previous prime is 691651688747. The next prime is 691651688821. The reversal of 691651688772 is 277886156196.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33152772 + ... + 33173627.

It is an arithmetic number, because the mean of its divisors is an integer number (37142784000).

Almost surely, 2^691651688772 is an apocalyptic number.

It is an amenable number.

691651688772 is an abundant number, since it is smaller than the sum of its proper divisors (1091201943228).

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

691651688772 is a wasteful number, since it uses less digits than its factorization.

691651688772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66326496 (or 66326494 counting only the distinct ones).

The product of its digits is 60963840, while the sum is 66.

The spelling of 691651688772 in words is "six hundred ninety-one billion, six hundred fifty-one million, six hundred eighty-eight thousand, seven hundred seventy-two".