1239685397 has 4 divisors (see below), whose sum is σ = 1240337376. Its totient is φ = 1239033420.

The previous prime is 1239685351. The next prime is 1239685409. The reversal of 1239685397 is 7935869321.

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 1239685397 - 2¹⁶ = 1239619861 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 (1239685897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 323129 + ... + 326942.

It is an arithmetic number, because the mean of its divisors is an integer number (310084344).

Almost surely, 2^1239685397 is an apocalyptic number.

It is an amenable number.

1239685397 is a deficient number, since it is larger than the sum of its proper divisors (651979).

1239685397 is an equidigital number, since it uses as much as digits as its factorization.

1239685397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651978.

The product of its digits is 2449440, while the sum is 53.

The square root of 1239685397 is about 35209.1663775216. The cubic root of 1239685397 is about 1074.2462058670.

The spelling of 1239685397 in words is "one billion, two hundred thirty-nine million, six hundred eighty-five thousand, three hundred ninety-seven".