26638921 has 4 divisors (see below), whose sum is σ = 26665600. Its totient is φ = 26612244.

The previous prime is 26638903. The next prime is 26638939. The reversal of 26638921 is 12983662.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (26638903) and next prime (26638939).

It is a cyclic number.

It is not a de Polignac number, because 26638921 - 2¹⁹ = 26114633 is a prime.

It is a super-2 number, since 2×26638921² = 1419264224088482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26638121) 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 3 ways as a sum of consecutive naturals, for example, 11781 + ... + 13858.

It is an arithmetic number, because the mean of its divisors is an integer number (6666400).

Almost surely, 2^26638921 is an apocalyptic number.

It is an amenable number.

26638921 is a deficient number, since it is larger than the sum of its proper divisors (26679).

26638921 is a wasteful number, since it uses less digits than its factorization.

26638921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26678.

The product of its digits is 31104, while the sum is 37.

The square root of 26638921 is about 5161.2906331653. The cubic root of 26638921 is about 298.6566641782.

The spelling of 26638921 in words is "twenty-six million, six hundred thirty-eight thousand, nine hundred twenty-one".