680921646 has 16 divisors (see below), whose sum is σ = 1366871808. Its totient is φ = 226135800.

The previous prime is 680921623. The next prime is 680921651. The reversal of 680921646 is 646129086.

It is a junction number, because it is equal to n+sod(n) for n = 680921598 and 680921607.

It is a congruent number.

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, 207760 + ... + 211011.

It is an arithmetic number, because the mean of its divisors is an integer number (85429488).

Almost surely, 2^680921646 is an apocalyptic number.

680921646 is an abundant number, since it is smaller than the sum of its proper divisors (685950162).

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

680921646 is a wasteful number, since it uses less digits than its factorization.

680921646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419047.

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 680921646 is about 26094.4753923125. The cubic root of 680921646 is about 879.7630413993.

The spelling of 680921646 in words is "six hundred eighty million, nine hundred twenty-one thousand, six hundred forty-six".