1390836409 has 2 divisors, whose sum is σ = 1390836410. Its totient is φ = 1390836408.

The previous prime is 1390836373. The next prime is 1390836437. The reversal of 1390836409 is 9046380931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1267004025 + 123832384 = 35595^2 + 11128^2 .

It is a cyclic number.

It is not a de Polignac number, because 1390836409 - 2²⁵ = 1357281977 is a prime.

It is not a weakly prime, because it can be changed into another prime (1390836439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695418204 + 695418205.

It is an arithmetic number, because the mean of its divisors is an integer number (695418205).

Almost surely, 2^1390836409 is an apocalyptic number.

It is an amenable number.

1390836409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1390836409 is an equidigital number, since it uses as much as digits as its factorization.

1390836409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 1390836409 is about 37293.9191960298. The cubic root of 1390836409 is about 1116.2428335647.

The spelling of 1390836409 in words is "one billion, three hundred ninety million, eight hundred thirty-six thousand, four hundred nine".