26979921 has 6 divisors (see below), whose sum is σ = 38971010. Its totient is φ = 17986608.

The previous prime is 26979917. The next prime is 26979941. The reversal of 26979921 is 12997962.

It can be written as a sum of positive squares in only one way, i.e., 17338896 + 9641025 = 4164^2 + 3105^2 .

It is not a de Polignac number, because 26979921 - 2² = 26979917 is a prime.

It is a super-2 number, since 2×26979921² = 1455832274332482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26979941) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1498876 + ... + 1498893.

Almost surely, 2^26979921 is an apocalyptic number.

It is an amenable number.

26979921 is a deficient number, since it is larger than the sum of its proper divisors (11991089).

26979921 is a wasteful number, since it uses less digits than its factorization.

26979921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2997775 (or 2997772 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 26979921 is about 5194.2199606871. The cubic root of 26979921 is about 299.9256148910.

The spelling of 26979921 in words is "twenty-six million, nine hundred seventy-nine thousand, nine hundred twenty-one".