1381625809 has 2 divisors, whose sum is σ = 1381625810. Its totient is φ = 1381625808.

The previous prime is 1381625807. The next prime is 1381625857. The reversal of 1381625809 is 9085261831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 810654784 + 570971025 = 28472^2 + 23895^2 .

It is a cyclic number.

It is not a de Polignac number, because 1381625809 - 2¹ = 1381625807 is a prime.

Together with 1381625807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1381625807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690812904 + 690812905.

It is an arithmetic number, because the mean of its divisors is an integer number (690812905).

Almost surely, 2^1381625809 is an apocalyptic number.

It is an amenable number.

1381625809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381625809 is an equidigital number, since it uses as much as digits as its factorization.

1381625809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 1381625809 is about 37170.2274542408. The cubic root of 1381625809 is about 1113.7733254298.

The spelling of 1381625809 in words is "one billion, three hundred eighty-one million, six hundred twenty-five thousand, eight hundred nine".