681577816 has 8 divisors (see below), whose sum is σ = 1277958420. Its totient is φ = 340788904.

The previous prime is 681577789. The next prime is 681577843. The reversal of 681577816 is 618775186.

It is an interprime number because it is at equal distance from previous prime (681577789) and next prime (681577843).

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 681577816.

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, 42598606 + ... + 42598621.

Almost surely, 2^681577816 is an apocalyptic number.

It is an amenable number.

681577816 is a deficient number, since it is larger than the sum of its proper divisors (596380604).

681577816 is a wasteful number, since it uses less digits than its factorization.

681577816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85197233 (or 85197229 counting only the distinct ones).

The product of its digits is 564480, while the sum is 49.

The square root of 681577816 is about 26107.0453326300. The cubic root of 681577816 is about 880.0455451634.

The spelling of 681577816 in words is "six hundred eighty-one million, five hundred seventy-seven thousand, eight hundred sixteen".