15510780491 has 2 divisors, whose sum is σ = 15510780492. Its totient is φ = 15510780490.

The previous prime is 15510780443. The next prime is 15510780497. The reversal of 15510780491 is 19408701551.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15510780491 - 2¹⁰ = 15510779467 is a prime.

It is a super-2 number, since 2×15510780491² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (15510780497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7755390245 + 7755390246.

It is an arithmetic number, because the mean of its divisors is an integer number (7755390246).

Almost surely, 2^15510780491 is an apocalyptic number.

15510780491 is a deficient number, since it is larger than the sum of its proper divisors (1).

15510780491 is an equidigital number, since it uses as much as digits as its factorization.

15510780491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 50400, while the sum is 41.

The spelling of 15510780491 in words is "fifteen billion, five hundred ten million, seven hundred eighty thousand, four hundred ninety-one".