139661407 has 2 divisors, whose sum is σ = 139661408. Its totient is φ = 139661406.

The previous prime is 139661399. The next prime is 139661449. The reversal of 139661407 is 704166931.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 139661407 - 2³ = 139661399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139661507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69830703 + 69830704.

It is an arithmetic number, because the mean of its divisors is an integer number (69830704).

Almost surely, 2^139661407 is an apocalyptic number.

139661407 is a deficient number, since it is larger than the sum of its proper divisors (1).

139661407 is an equidigital number, since it uses as much as digits as its factorization.

139661407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 139661407 is about 11817.8427388420. The cubic root of 139661407 is about 518.8304669872.

The spelling of 139661407 in words is "one hundred thirty-nine million, six hundred sixty-one thousand, four hundred seven".