90561551 has 4 divisors (see below), whose sum is σ = 90581400. Its totient is φ = 90541704.

The previous prime is 90561547. The next prime is 90561563. The reversal of 90561551 is 15516509.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15516509 = 61 ⋅254369.

It is a cyclic number.

It is not a de Polignac number, because 90561551 - 2² = 90561547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90561851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 740 + ... + 13478.

It is an arithmetic number, because the mean of its divisors is an integer number (22645350).

Almost surely, 2^90561551 is an apocalyptic number.

90561551 is a deficient number, since it is larger than the sum of its proper divisors (19849).

90561551 is a wasteful number, since it uses less digits than its factorization.

90561551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19848.

The product of its (nonzero) digits is 6750, while the sum is 32.

The square root of 90561551 is about 9516.3832940881. The cubic root of 90561551 is about 449.0705937089.

The spelling of 90561551 in words is "ninety million, five hundred sixty-one thousand, five hundred fifty-one".