15400993 has 2 divisors, whose sum is σ = 15400994. Its totient is φ = 15400992.

The previous prime is 15400969. The next prime is 15400999. The reversal of 15400993 is 39900451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14961424 + 439569 = 3868^2 + 663^2 .

It is a cyclic number.

It is not a de Polignac number, because 15400993 - 2⁹ = 15400481 is a prime.

It is not a weakly prime, because it can be changed into another prime (15400999) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7700496 + 7700497.

It is an arithmetic number, because the mean of its divisors is an integer number (7700497).

Almost surely, 2^15400993 is an apocalyptic number.

It is an amenable number.

15400993 is a deficient number, since it is larger than the sum of its proper divisors (1).

15400993 is an equidigital number, since it uses as much as digits as its factorization.

15400993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 15400993 is about 3924.4098919455. The cubic root of 15400993 is about 248.7995408176.

The spelling of 15400993 in words is "fifteen million, four hundred thousand, nine hundred ninety-three".