26820981 has 24 divisors (see below), whose sum is σ = 42631680. Its totient is φ = 16247880.

The previous prime is 26820979. The next prime is 26820991. The reversal of 26820981 is 18902862.

26820981 = 205² + 206² + ... + 446².

It is not a de Polignac number, because 26820981 - 2¹ = 26820979 is a prime.

It is a super-2 number, since 2×26820981² = 1438730043604722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26820931) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10860 + ... + 13098.

It is an arithmetic number, because the mean of its divisors is an integer number (1776320).

Almost surely, 2^26820981 is an apocalyptic number.

It is an amenable number.

26820981 is a deficient number, since it is larger than the sum of its proper divisors (15810699).

26820981 is a wasteful number, since it uses less digits than its factorization.

26820981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2278 (or 2253 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 26820981 is about 5178.8976626305. The cubic root of 26820981 is about 299.3354958676.

The spelling of 26820981 in words is "twenty-six million, eight hundred twenty thousand, nine hundred eighty-one".