1397431669 has 4 divisors (see below), whose sum is σ = 1397509344. Its totient is φ = 1397353996.

The previous prime is 1397431601. The next prime is 1397431681. The reversal of 1397431669 is 9661347931.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1397431669 is a prime.

It is a super-2 number, since 2×1397431669² = 3905630539048251122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1397431069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3624 + ... + 52990.

It is an arithmetic number, because the mean of its divisors is an integer number (349377336).

Almost surely, 2^1397431669 is an apocalyptic number.

It is an amenable number.

1397431669 is a deficient number, since it is larger than the sum of its proper divisors (77675).

1397431669 is an equidigital number, since it uses as much as digits as its factorization.

1397431669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77674.

The product of its digits is 734832, while the sum is 49.

The square root of 1397431669 is about 37382.2373460979. The cubic root of 1397431669 is about 1118.0044367855.

The spelling of 1397431669 in words is "one billion, three hundred ninety-seven million, four hundred thirty-one thousand, six hundred sixty-nine".