90811778 has 4 divisors (see below), whose sum is σ = 136217670. Its totient is φ = 45405888.

The previous prime is 90811771. The next prime is 90811793. The reversal of 90811778 is 87711809.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 70946929 + 19864849 = 8423^2 + 4457^2 .

It is not an unprimeable number, because it can be changed into a prime (90811771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22702943 + ... + 22702946.

Almost surely, 2^90811778 is an apocalyptic number.

90811778 is a deficient number, since it is larger than the sum of its proper divisors (45405892).

90811778 is a wasteful number, since it uses less digits than its factorization.

90811778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45405891.

The product of its (nonzero) digits is 28224, while the sum is 41.

The square root of 90811778 is about 9529.5213940680. The cubic root of 90811778 is about 449.4838163556.

The spelling of 90811778 in words is "ninety million, eight hundred eleven thousand, seven hundred seventy-eight".