15491994877 has 2 divisors, whose sum is σ = 15491994878. Its totient is φ = 15491994876.

The previous prime is 15491994841. The next prime is 15491994913. The reversal of 15491994877 is 77849919451.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (15491994841) and next prime (15491994913).

It can be written as a sum of positive squares in only one way, i.e., 11619546436 + 3872448441 = 107794^2 + 62229^2 .

It is an emirp because it is prime and its reverse (77849919451) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15491994877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15491994577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7745997438 + 7745997439.

It is an arithmetic number, because the mean of its divisors is an integer number (7745997439).

Almost surely, 2^15491994877 is an apocalyptic number.

It is an amenable number.

15491994877 is a deficient number, since it is larger than the sum of its proper divisors (1).

15491994877 is an equidigital number, since it uses as much as digits as its factorization.

15491994877 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22861440, while the sum is 64.

The spelling of 15491994877 in words is "fifteen billion, four hundred ninety-one million, nine hundred ninety-four thousand, eight hundred seventy-seven".