90840561 has 12 divisors (see below), whose sum is σ = 140895792. Its totient is φ = 51908808.

The previous prime is 90840559. The next prime is 90840601. The reversal of 90840561 is 16504809.

It is not a de Polignac number, because 90840561 - 2¹ = 90840559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (90840521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 308835 + ... + 309128.

It is an arithmetic number, because the mean of its divisors is an integer number (11741316).

Almost surely, 2^90840561 is an apocalyptic number.

It is an amenable number.

90840561 is a deficient number, since it is larger than the sum of its proper divisors (50055231).

90840561 is a wasteful number, since it uses less digits than its factorization.

90840561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617980 (or 617973 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 90840561 is about 9531.0314761835. The cubic root of 90840561 is about 449.5312996460.

The spelling of 90840561 in words is "ninety million, eight hundred forty thousand, five hundred sixty-one".