15651491 has 2 divisors, whose sum is σ = 15651492. Its totient is φ = 15651490.

The previous prime is 15651479. The next prime is 15651499. The reversal of 15651491 is 19415651.

It is a strong prime.

It is an emirp because it is prime and its reverse (19415651) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15651491 is a prime.

It is not a weakly prime, because it can be changed into another prime (15651499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7825745 + 7825746.

It is an arithmetic number, because the mean of its divisors is an integer number (7825746).

Almost surely, 2^15651491 is an apocalyptic number.

15651491 is a deficient number, since it is larger than the sum of its proper divisors (1).

15651491 is an equidigital number, since it uses as much as digits as its factorization.

15651491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5400, while the sum is 32.

The square root of 15651491 is about 3956.1965320242. The cubic root of 15651491 is about 250.1412055623.

The spelling of 15651491 in words is "fifteen million, six hundred fifty-one thousand, four hundred ninety-one".