15400391 has 2 divisors, whose sum is σ = 15400392. Its totient is φ = 15400390.

The previous prime is 15400337. The next prime is 15400433. The reversal of 15400391 is 19300451.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15400391 - 2⁶ = 15400327 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15400291) 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 as a sum of consecutive naturals, namely, 7700195 + 7700196.

It is an arithmetic number, because the mean of its divisors is an integer number (7700196).

Almost surely, 2^15400391 is an apocalyptic number.

15400391 is a deficient number, since it is larger than the sum of its proper divisors (1).

15400391 is an equidigital number, since it uses as much as digits as its factorization.

15400391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 15400391 is about 3924.3331917665. Note that the first 3 decimals coincide. The cubic root of 15400391 is about 248.7962990510.

The spelling of 15400391 in words is "fifteen million, four hundred thousand, three hundred ninety-one".