90905445 has 24 divisors (see below), whose sum is σ = 158493816. Its totient is φ = 48198528.

The previous prime is 90905377. The next prime is 90905447. The reversal of 90905445 is 54450909.

90905445 is nontrivially palindromic in base 16.

It can be written as a sum of positive squares in 4 ways, for example, as 43046721 + 47858724 = 6561^2 + 6918^2 .

It is not a de Polignac number, because 90905445 - 2⁷ = 90905317 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90905447) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1947 + ... + 13623.

It is an arithmetic number, because the mean of its divisors is an integer number (6603909).

Almost surely, 2^90905445 is an apocalyptic number.

90905445 is the 7785-th pentagonal number.

It is an amenable number.

90905445 is a deficient number, since it is larger than the sum of its proper divisors (67588371).

90905445 is a wasteful number, since it uses less digits than its factorization.

90905445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11861 (or 11858 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 90905445 is about 9534.4346974532. The cubic root of 90905445 is about 449.6383019472.

It can be divided in two parts, 9090 and 5445, that added together give a triangular number (14535 = T₁₇₀).

The spelling of 90905445 in words is "ninety million, nine hundred five thousand, four hundred forty-five".