681621188 has 48 divisors (see below), whose sum is σ = 1281256704. Its totient is φ = 316170240.

The previous prime is 681621173. The next prime is 681621197. The reversal of 681621188 is 881126186.

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, 2191553 + ... + 2191863.

It is an arithmetic number, because the mean of its divisors is an integer number (26692848).

Almost surely, 2^681621188 is an apocalyptic number.

681621188 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

681621188 is a deficient number, since it is larger than the sum of its proper divisors (599635516).

681621188 is a wasteful number, since it uses less digits than its factorization.

681621188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692 (or 690 counting only the distinct ones).

The product of its digits is 36864, while the sum is 41.

The square root of 681621188 is about 26107.8759764175. The cubic root of 681621188 is about 880.0642119123.

The spelling of 681621188 in words is "six hundred eighty-one million, six hundred twenty-one thousand, one hundred eighty-eight".