681639099 has 16 divisors (see below), whose sum is σ = 917495808. Its totient is φ = 450116352.

The previous prime is 681639061. The next prime is 681639103. The reversal of 681639099 is 990936186.

It is not a de Polignac number, because 681639099 - 2⁸ = 681638843 is a prime.

It is a super-2 number, since 2×681639099² = 929263722571063602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (681639019) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 336939 + ... + 338955.

It is an arithmetic number, because the mean of its divisors is an integer number (57343488).

Almost surely, 2^681639099 is an apocalyptic number.

681639099 is a deficient number, since it is larger than the sum of its proper divisors (235856709).

681639099 is a wasteful number, since it uses less digits than its factorization.

681639099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3034.

The product of its (nonzero) digits is 629856, while the sum is 51.

The square root of 681639099 is about 26108.2189932596. The cubic root of 681639099 is about 880.0719203444.

The spelling of 681639099 in words is "six hundred eighty-one million, six hundred thirty-nine thousand, ninety-nine".