26978981 has 2 divisors, whose sum is σ = 26978982. Its totient is φ = 26978980.

The previous prime is 26978971. The next prime is 26979061. The reversal of 26978981 is 18987962.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22714756 + 4264225 = 4766^2 + 2065^2 .

It is a cyclic number.

It is not a de Polignac number, because 26978981 - 2¹⁴ = 26962597 is a prime.

It is a super-2 number, since 2×26978981² = 1455730831596722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26978951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13489490 + 13489491.

It is an arithmetic number, because the mean of its divisors is an integer number (13489491).

Almost surely, 2^26978981 is an apocalyptic number.

It is an amenable number.

26978981 is a deficient number, since it is larger than the sum of its proper divisors (1).

26978981 is an equidigital number, since it uses as much as digits as its factorization.

26978981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 50.

The square root of 26978981 is about 5194.1294747051. The cubic root of 26978981 is about 299.9221316420.

The spelling of 26978981 in words is "twenty-six million, nine hundred seventy-eight thousand, nine hundred eighty-one".