90388861 has 2 divisors, whose sum is σ = 90388862. Its totient is φ = 90388860.

The previous prime is 90388843. The next prime is 90388927. The reversal of 90388861 is 16888309.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50623225 + 39765636 = 7115^2 + 6306^2 .

It is a cyclic number.

It is not a de Polignac number, because 90388861 - 2⁷ = 90388733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90388841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45194430 + 45194431.

It is an arithmetic number, because the mean of its divisors is an integer number (45194431).

Almost surely, 2^90388861 is an apocalyptic number.

It is an amenable number.

90388861 is a deficient number, since it is larger than the sum of its proper divisors (1).

90388861 is an equidigital number, since it uses as much as digits as its factorization.

90388861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 90388861 is about 9507.3056645929. The cubic root of 90388861 is about 448.7849708549.

The spelling of 90388861 in words is "ninety million, three hundred eighty-eight thousand, eight hundred sixty-one".