90909866 has 4 divisors (see below), whose sum is σ = 136364802. Its totient is φ = 45454932.

The previous prime is 90909859. The next prime is 90909877. The reversal of 90909866 is 66890909.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66890909 = 97 ⋅689597.

It can be written as a sum of positive squares in only one way, i.e., 48594841 + 42315025 = 6971^2 + 6505^2 .

It is a super-2 number, since 2×90909866² = 16529207472275912, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 90909866.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22727465 + ... + 22727468.

Almost surely, 2^90909866 is an apocalyptic number.

90909866 is a deficient number, since it is larger than the sum of its proper divisors (45454936).

90909866 is a wasteful number, since it uses less digits than its factorization.

90909866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45454935.

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 90909866 is about 9534.6665384795. Note that the first 3 decimals coincide. The cubic root of 90909866 is about 449.6455909081.

The spelling of 90909866 in words is "ninety million, nine hundred nine thousand, eight hundred sixty-six".