681397628 has 6 divisors (see below), whose sum is σ = 1192445856. Its totient is φ = 340698812.

The previous prime is 681397603. The next prime is 681397643. The reversal of 681397628 is 826793186.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85174700 + ... + 85174707.

It is an arithmetic number, because the mean of its divisors is an integer number (198740976).

Almost surely, 2^681397628 is an apocalyptic number.

It is an amenable number.

681397628 is a deficient number, since it is larger than the sum of its proper divisors (511048228).

681397628 is a wasteful number, since it uses less digits than its factorization.

681397628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170349411 (or 170349409 counting only the distinct ones).

The product of its digits is 870912, while the sum is 50.

The square root of 681397628 is about 26103.5941586595. The cubic root of 681397628 is about 879.9679860943.

The spelling of 681397628 in words is "six hundred eighty-one million, three hundred ninety-seven thousand, six hundred twenty-eight".