1389890691 has 32 divisors (see below), whose sum is σ = 2356462080. Its totient is φ = 793140768.

The previous prime is 1389890683. The next prime is 1389890701. The reversal of 1389890691 is 1960989831.

It is not a de Polignac number, because 1389890691 - 2³ = 1389890683 is a prime.

It is a super-2 number, since 2×1389890691² = 3863592265856914962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1389890191) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 146020 + ... + 155246.

It is an arithmetic number, because the mean of its divisors is an integer number (73639440).

Almost surely, 2^1389890691 is an apocalyptic number.

1389890691 is a deficient number, since it is larger than the sum of its proper divisors (966571389).

1389890691 is an equidigital number, since it uses as much as digits as its factorization.

1389890691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10040 (or 10034 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 54.

The square root of 1389890691 is about 37281.2377879276. The cubic root of 1389890691 is about 1115.9897747358.

The spelling of 1389890691 in words is "one billion, three hundred eighty-nine million, eight hundred ninety thousand, six hundred ninety-one".