26288991 has 12 divisors (see below), whose sum is σ = 38540632. Its totient is φ = 17264016.

The previous prime is 26288963. The next prime is 26289001. The reversal of 26288991 is 19988262.

It is not a de Polignac number, because 26288991 - 2⁵ = 26288959 is a prime.

It is a super-2 number, since 2×26288991² = 1382222095596162, 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 (26288921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21196 + ... + 22401.

Almost surely, 2^26288991 is an apocalyptic number.

26288991 is a deficient number, since it is larger than the sum of its proper divisors (12251641).

26288991 is a wasteful number, since it uses less digits than its factorization.

26288991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43670 (or 43667 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 26288991 is about 5127.2791029941. The cubic root of 26288991 is about 297.3431737054.

It can be divided in two parts, 262 and 88991, that added together give a triangular number (89253 = T₄₂₂).

The spelling of 26288991 in words is "twenty-six million, two hundred eighty-eight thousand, nine hundred ninety-one".