139829681 has 2 divisors, whose sum is σ = 139829682. Its totient is φ = 139829680.

The previous prime is 139829621. The next prime is 139829687. The reversal of 139829681 is 186928931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 134189056 + 5640625 = 11584^2 + 2375^2 .

It is a cyclic number.

It is not a de Polignac number, because 139829681 - 2⁶ = 139829617 is a prime.

It is a super-2 number, since 2×139829681² = 39104679377123522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (139829687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69914840 + 69914841.

It is an arithmetic number, because the mean of its divisors is an integer number (69914841).

Almost surely, 2^139829681 is an apocalyptic number.

It is an amenable number.

139829681 is a deficient number, since it is larger than the sum of its proper divisors (1).

139829681 is an equidigital number, since it uses as much as digits as its factorization.

139829681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 47.

The square root of 139829681 is about 11824.9600844992. The cubic root of 139829681 is about 519.0387579754.

The spelling of 139829681 in words is "one hundred thirty-nine million, eight hundred twenty-nine thousand, six hundred eighty-one".