90815567 has 2 divisors, whose sum is σ = 90815568. Its totient is φ = 90815566.

The previous prime is 90815563. The next prime is 90815591. The reversal of 90815567 is 76551809.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 90815567 - 2² = 90815563 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90815561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45407783 + 45407784.

It is an arithmetic number, because the mean of its divisors is an integer number (45407784).

Almost surely, 2^90815567 is an apocalyptic number.

90815567 is a deficient number, since it is larger than the sum of its proper divisors (1).

90815567 is an equidigital number, since it uses as much as digits as its factorization.

90815567 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 41.

The square root of 90815567 is about 9529.7201952628. The cubic root of 90815567 is about 449.4900676391.

The spelling of 90815567 in words is "ninety million, eight hundred fifteen thousand, five hundred sixty-seven".