15649993 has 2 divisors, whose sum is σ = 15649994. Its totient is φ = 15649992.

The previous prime is 15649951. The next prime is 15650003. The reversal of 15649993 is 39994651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9314704 + 6335289 = 3052^2 + 2517^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15649993 is a prime.

It is a nialpdrome in base 16.

It is not a weakly prime, because it can be changed into another prime (15649093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7824996 + 7824997.

It is an arithmetic number, because the mean of its divisors is an integer number (7824997).

Almost surely, 2^15649993 is an apocalyptic number.

It is an amenable number.

15649993 is a deficient number, since it is larger than the sum of its proper divisors (1).

15649993 is an equidigital number, since it uses as much as digits as its factorization.

15649993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 262440, while the sum is 46.

The square root of 15649993 is about 3956.0072042402. The cubic root of 15649993 is about 250.1332249918.

The spelling of 15649993 in words is "fifteen million, six hundred forty-nine thousand, nine hundred ninety-three".