90851561 has 4 divisors (see below), whose sum is σ = 92964432. Its totient is φ = 88738692.

The previous prime is 90851557. The next prime is 90851569. The reversal of 90851561 is 16515809.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 90851561 - 2² = 90851557 is a prime.

It is a super-2 number, since 2×90851561² = 16508012272273442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90851569) 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 in 3 ways as a sum of consecutive naturals, for example, 1056371 + ... + 1056456.

It is an arithmetic number, because the mean of its divisors is an integer number (23241108).

Almost surely, 2^90851561 is an apocalyptic number.

It is an amenable number.

90851561 is a deficient number, since it is larger than the sum of its proper divisors (2112871).

90851561 is a wasteful number, since it uses less digits than its factorization.

90851561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2112870.

The product of its (nonzero) digits is 10800, while the sum is 35.

The square root of 90851561 is about 9531.6085211259. The cubic root of 90851561 is about 449.5494436874.

The spelling of 90851561 in words is "ninety million, eight hundred fifty-one thousand, five hundred sixty-one".