139015081 has 2 divisors, whose sum is σ = 139015082. Its totient is φ = 139015080.

The previous prime is 139015061. The next prime is 139015091. The reversal of 139015081 is 180510931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126765081 + 12250000 = 11259^2 + 3500^2 .

It is a cyclic number.

It is not a de Polignac number, because 139015081 - 2⁹ = 139014569 is a prime.

It is a super-2 number, since 2×139015081² = 38650385490873122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (139015061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69507540 + 69507541.

It is an arithmetic number, because the mean of its divisors is an integer number (69507541).

Almost surely, 2^139015081 is an apocalyptic number.

It is an amenable number.

139015081 is a deficient number, since it is larger than the sum of its proper divisors (1).

139015081 is an equidigital number, since it uses as much as digits as its factorization.

139015081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 28.

The square root of 139015081 is about 11790.4656820670. The cubic root of 139015081 is about 518.0288801397.

It can be divided in two parts, 1390 and 15081, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 139015081 in words is "one hundred thirty-nine million, fifteen thousand, eighty-one".