91111051 has 4 divisors (see below), whose sum is σ = 93049632. Its totient is φ = 89172472.

The previous prime is 91111049. The next prime is 91111063. The reversal of 91111051 is 15011119.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91111051 - 2¹ = 91111049 is a prime.

It is a super-2 number, since 2×91111051² = 16602447228649202, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91111021) 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, 969220 + ... + 969313.

It is an arithmetic number, because the mean of its divisors is an integer number (23262408).

Almost surely, 2^91111051 is an apocalyptic number.

91111051 is a deficient number, since it is larger than the sum of its proper divisors (1938581).

91111051 is a wasteful number, since it uses less digits than its factorization.

91111051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1938580.

The product of its (nonzero) digits is 45, while the sum is 19.

The square root of 91111051 is about 9545.2108934271. The cubic root of 91111051 is about 449.9770375114.

The spelling of 91111051 in words is "ninety-one million, one hundred eleven thousand, fifty-one".