91555251 has 8 divisors (see below), whose sum is σ = 129254544. Its totient is φ = 57446400.

The previous prime is 91555241. The next prime is 91555259. The reversal of 91555251 is 15255519.

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

It is not a de Polignac number, because 91555251 - 2⁹ = 91554739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91555259) 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, 897550 + ... + 897651.

It is an arithmetic number, because the mean of its divisors is an integer number (16156818).

Almost surely, 2^91555251 is an apocalyptic number.

91555251 is a deficient number, since it is larger than the sum of its proper divisors (37699293).

91555251 is a wasteful number, since it uses less digits than its factorization.

91555251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1795221.

The product of its digits is 11250, while the sum is 33.

The square root of 91555251 is about 9568.4508150484. The cubic root of 91555251 is about 450.7071203630.

It can be divided in two parts, 91555 and 251, that added together give a triangular number (91806 = T₄₂₈).

The spelling of 91555251 in words is "ninety-one million, five hundred fifty-five thousand, two hundred fifty-one".