26556989 has 2 divisors, whose sum is σ = 26556990. Its totient is φ = 26556988.

The previous prime is 26556983. The next prime is 26557001. The reversal of 26556989 is 98965562.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26112100 + 444889 = 5110^2 + 667^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26556989 is a prime.

It is a super-2 number, since 2×26556989² = 1410547329492242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26556983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13278494 + 13278495.

It is an arithmetic number, because the mean of its divisors is an integer number (13278495).

Almost surely, 2^26556989 is an apocalyptic number.

It is an amenable number.

26556989 is a deficient number, since it is larger than the sum of its proper divisors (1).

26556989 is an equidigital number, since it uses as much as digits as its factorization.

26556989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1166400, while the sum is 50.

The square root of 26556989 is about 5153.3473587562. The cubic root of 26556989 is about 298.3501619323.

The spelling of 26556989 in words is "twenty-six million, five hundred fifty-six thousand, nine hundred eighty-nine".