91561893 has 8 divisors (see below), whose sum is σ = 128508000. Its totient is φ = 57828528.

The previous prime is 91561891. The next prime is 91561907. The reversal of 91561893 is 39816519.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91561893 - 2¹ = 91561891 is a prime.

It is a super-3 number, since 3×91561893³ (a number of 25 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91561891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 803118 + ... + 803231.

It is an arithmetic number, because the mean of its divisors is an integer number (16063500).

Almost surely, 2^91561893 is an apocalyptic number.

It is an amenable number.

91561893 is a deficient number, since it is larger than the sum of its proper divisors (36946107).

91561893 is a wasteful number, since it uses less digits than its factorization.

91561893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1606371.

The product of its digits is 58320, while the sum is 42.

The square root of 91561893 is about 9568.7978868821. The cubic root of 91561893 is about 450.7180191527.

The spelling of 91561893 in words is "ninety-one million, five hundred sixty-one thousand, eight hundred ninety-three".