26217891 has 64 divisors (see below), whose sum is σ = 48000000. Its totient is φ = 14097888.

The previous prime is 26217871. The next prime is 26217899. The reversal of 26217891 is 19871262.

It is not a de Polignac number, because 26217891 - 2¹⁰ = 26216867 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26217899) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 175885 + ... + 176033.

It is an arithmetic number, because the mean of its divisors is an integer number (750000).

Almost surely, 2^26217891 is an apocalyptic number.

26217891 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

26217891 is a deficient number, since it is larger than the sum of its proper divisors (21782109).

26217891 is a wasteful number, since it uses less digits than its factorization.

26217891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 178 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 26217891 is about 5120.3409066194. The cubic root of 26217891 is about 297.0748714412.

The spelling of 26217891 in words is "twenty-six million, two hundred seventeen thousand, eight hundred ninety-one".