90887878909 has 2 divisors, whose sum is σ = 90887878910. Its totient is φ = 90887878908.

The previous prime is 90887878897. The next prime is 90887878919. The reversal of 90887878909 is 90987878809.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58910571225 + 31977307684 = 242715^2 + 178822^2 .

It is a cyclic number.

It is not a de Polignac number, because 90887878909 - 2⁵ = 90887878877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90887878919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45443939454 + 45443939455.

It is an arithmetic number, because the mean of its divisors is an integer number (45443939455).

Almost surely, 2^90887878909 is an apocalyptic number.

It is an amenable number.

90887878909 is a deficient number, since it is larger than the sum of its proper divisors (1).

90887878909 is an equidigital number, since it uses as much as digits as its factorization.

90887878909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 146313216, while the sum is 73.

The spelling of 90887878909 in words is "ninety billion, eight hundred eighty-seven million, eight hundred seventy-eight thousand, nine hundred nine".