15624999491 has 2 divisors, whose sum is σ = 15624999492. Its totient is φ = 15624999490.

The previous prime is 15624999479. The next prime is 15624999521. The reversal of 15624999491 is 19499942651.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15624999491 is a prime.

It is a super-3 number, since 3×15624999491³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 15624999491.

It is not a weakly prime, because it can be changed into another prime (15624929491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7812499745 + 7812499746.

It is an arithmetic number, because the mean of its divisors is an integer number (7812499746).

Almost surely, 2^15624999491 is an apocalyptic number.

15624999491 is a deficient number, since it is larger than the sum of its proper divisors (1).

15624999491 is an equidigital number, since it uses as much as digits as its factorization.

15624999491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6298560, while the sum is 59.

The spelling of 15624999491 in words is "fifteen billion, six hundred twenty-four million, nine hundred ninety-nine thousand, four hundred ninety-one".