681000139 has 2 divisors, whose sum is σ = 681000140. Its totient is φ = 681000138.

The previous prime is 681000113. The next prime is 681000149. The reversal of 681000139 is 931000186.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 681000139 - 2⁵ = 681000107 is a prime.

It is a super-2 number, since 2×681000139² = 927522378636038642, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (681000149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340500069 + 340500070.

It is an arithmetic number, because the mean of its divisors is an integer number (340500070).

Almost surely, 2^681000139 is an apocalyptic number.

681000139 is a deficient number, since it is larger than the sum of its proper divisors (1).

681000139 is an equidigital number, since it uses as much as digits as its factorization.

681000139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 681000139 is about 26095.9793646454. The cubic root of 681000139 is about 879.7968448908.

The spelling of 681000139 in words is "six hundred eighty-one million, one hundred thirty-nine", and thus it is an aban number.