90815761 has 4 divisors (see below), whose sum is σ = 90973732. Its totient is φ = 90657792.

The previous prime is 90815749. The next prime is 90815773. The reversal of 90815761 is 16751809.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16751809 = 67 ⋅250027.

It is an interprime number because it is at equal distance from previous prime (90815749) and next prime (90815773).

It can be written as a sum of positive squares in 2 ways, for example, as 68310225 + 22505536 = 8265^2 + 4744^2 .

It is a cyclic number.

It is not a de Polignac number, because 90815761 - 2⁵ = 90815729 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 90815761.

It is not an unprimeable number, because it can be changed into a prime (90815701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78120 + ... + 79273.

It is an arithmetic number, because the mean of its divisors is an integer number (22743433).

Almost surely, 2^90815761 is an apocalyptic number.

It is an amenable number.

90815761 is a deficient number, since it is larger than the sum of its proper divisors (157971).

90815761 is a wasteful number, since it uses less digits than its factorization.

90815761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157970.

The product of its (nonzero) digits is 15120, while the sum is 37.

The square root of 90815761 is about 9529.7303739403. The cubic root of 90815761 is about 449.4903877054.

The spelling of 90815761 in words is "ninety million, eight hundred fifteen thousand, seven hundred sixty-one".