16815261887 has 2 divisors, whose sum is σ = 16815261888. Its totient is φ = 16815261886.

The previous prime is 16815261821. The next prime is 16815261913. The reversal of 16815261887 is 78816251861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16815261887 - 2¹² = 16815257791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16815260887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8407630943 + 8407630944.

It is an arithmetic number, because the mean of its divisors is an integer number (8407630944).

Almost surely, 2^16815261887 is an apocalyptic number.

16815261887 is a deficient number, since it is larger than the sum of its proper divisors (1).

16815261887 is an equidigital number, since it uses as much as digits as its factorization.

16815261887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1290240, while the sum is 53.

The spelling of 16815261887 in words is "sixteen billion, eight hundred fifteen million, two hundred sixty-one thousand, eight hundred eighty-seven".