15501615491 has 2 divisors, whose sum is σ = 15501615492. Its totient is φ = 15501615490.

The previous prime is 15501615487. The next prime is 15501615511. The reversal of 15501615491 is 19451610551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15501615491 - 2² = 15501615487 is a prime.

It is a super-2 number, since 2×15501615491² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (15501615091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7750807745 + 7750807746.

It is an arithmetic number, because the mean of its divisors is an integer number (7750807746).

Almost surely, 2^15501615491 is an apocalyptic number.

15501615491 is a deficient number, since it is larger than the sum of its proper divisors (1).

15501615491 is an equidigital number, since it uses as much as digits as its factorization.

15501615491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27000, while the sum is 38.

The spelling of 15501615491 in words is "fifteen billion, five hundred one million, six hundred fifteen thousand, four hundred ninety-one".