1390631969 has 4 divisors (see below), whose sum is σ = 1409681796. Its totient is φ = 1371582144.

The previous prime is 1390631951. The next prime is 1390631981. The reversal of 1390631969 is 9691360931.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 823001344 + 567630625 = 28688^2 + 23825^2 .

It is a cyclic number.

It is not a de Polignac number, because 1390631969 - 2²⁴ = 1373854753 is a prime.

It is a super-2 number, since 2×1390631969² = 3867714546409633922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1390631989) 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, 9524804 + ... + 9524949.

It is an arithmetic number, because the mean of its divisors is an integer number (352420449).

Almost surely, 2^1390631969 is an apocalyptic number.

It is an amenable number.

1390631969 is a deficient number, since it is larger than the sum of its proper divisors (19049827).

1390631969 is an equidigital number, since it uses as much as digits as its factorization.

1390631969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19049826.

The product of its (nonzero) digits is 236196, while the sum is 47.

The square root of 1390631969 is about 37291.1781658880. The cubic root of 1390631969 is about 1116.1881384508.

The spelling of 1390631969 in words is "one billion, three hundred ninety million, six hundred thirty-one thousand, nine hundred sixty-nine".