139866397 has 4 divisors (see below), whose sum is σ = 152581536. Its totient is φ = 127151260.

The previous prime is 139866383. The next prime is 139866431. The reversal of 139866397 is 793668931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 139866397 - 2¹¹ = 139864349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139866347) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6357553 + ... + 6357574.

It is an arithmetic number, because the mean of its divisors is an integer number (38145384).

Almost surely, 2^139866397 is an apocalyptic number.

It is an amenable number.

139866397 is a deficient number, since it is larger than the sum of its proper divisors (12715139).

139866397 is a wasteful number, since it uses less digits than its factorization.

139866397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12715138.

The product of its digits is 1469664, while the sum is 52.

The square root of 139866397 is about 11826.5124614148. The cubic root of 139866397 is about 519.0841831412.

The spelling of 139866397 in words is "one hundred thirty-nine million, eight hundred sixty-six thousand, three hundred ninety-seven".