91889261 has 8 divisors (see below), whose sum is σ = 93368760. Its totient is φ = 90415872.

The previous prime is 91889243. The next prime is 91889293. The reversal of 91889261 is 16298819.

It can be written as a sum of positive squares in 4 ways, for example, as 40322500 + 51566761 = 6350^2 + 7181^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 91889261 - 2¹⁸ = 91627117 is a prime.

It is a super-2 number, since 2×91889261² = 16887272574252242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91889221) 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, 35921 + ... + 38393.

It is an arithmetic number, because the mean of its divisors is an integer number (11671095).

Almost surely, 2^91889261 is an apocalyptic number.

It is an amenable number.

91889261 is a deficient number, since it is larger than the sum of its proper divisors (1479499).

91889261 is a wasteful number, since it uses less digits than its factorization.

91889261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3055.

The product of its digits is 62208, while the sum is 44.

The square root of 91889261 is about 9585.8886390360. Note that the first 3 decimals coincide. The cubic root of 91889261 is about 451.2545420465.

The spelling of 91889261 in words is "ninety-one million, eight hundred eighty-nine thousand, two hundred sixty-one".