139321531 has 2 divisors, whose sum is σ = 139321532. Its totient is φ = 139321530.

The previous prime is 139321519. The next prime is 139321543. The reversal of 139321531 is 135123931.

139321531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (139321519) and next prime (139321543).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139321531 is a prime.

It is a super-2 number, since 2×139321531² = 38820978000367922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 139321531.

It is not a weakly prime, because it can be changed into another prime (139321561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69660765 + 69660766.

It is an arithmetic number, because the mean of its divisors is an integer number (69660766).

Almost surely, 2^139321531 is an apocalyptic number.

139321531 is a deficient number, since it is larger than the sum of its proper divisors (1).

139321531 is an equidigital number, since it uses as much as digits as its factorization.

139321531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2430, while the sum is 28.

The square root of 139321531 is about 11803.4541978185. The cubic root of 139321531 is about 518.4092547974.

The spelling of 139321531 in words is "one hundred thirty-nine million, three hundred twenty-one thousand, five hundred thirty-one".