721673673780 has 48 divisors (see below), whose sum is σ = 2020992684480. Its totient is φ = 192417132288.

The previous prime is 721673673779. The next prime is 721673673839. The reversal of 721673673780 is 87376376127.

It is a self number, because there is not a number n which added to its sum of digits gives 721673673780.

It is a congruent number.

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, 511449 + ... + 1305728.

It is an arithmetic number, because the mean of its divisors is an integer number (42104014260).

Almost surely, 2^721673673780 is an apocalyptic number.

It is an amenable number.

721673673780 is an abundant number, since it is smaller than the sum of its proper divisors (1299319010700).

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

721673673780 is a wasteful number, since it uses less digits than its factorization.

721673673780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1823808 (or 1823806 counting only the distinct ones).

The product of its (nonzero) digits is 12446784, while the sum is 57.

The spelling of 721673673780 in words is "seven hundred twenty-one billion, six hundred seventy-three million, six hundred seventy-three thousand, seven hundred eighty".