26139989 has 2 divisors, whose sum is σ = 26139990. Its totient is φ = 26139988.

The previous prime is 26139979. The next prime is 26140007. The reversal of 26139989 is 98993162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26112100 + 27889 = 5110^2 + 167^2 .

It is a cyclic number.

It is not a de Polignac number, because 26139989 - 2¹⁶ = 26074453 is a prime.

It is a Sophie Germain 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 (26139979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13069994 + 13069995.

It is an arithmetic number, because the mean of its divisors is an integer number (13069995).

Almost surely, 2^26139989 is an apocalyptic number.

It is an amenable number.

26139989 is a deficient number, since it is larger than the sum of its proper divisors (1).

26139989 is an equidigital number, since it uses as much as digits as its factorization.

26139989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 47.

The square root of 26139989 is about 5112.7281367192. The cubic root of 26139989 is about 296.7803437323.

The spelling of 26139989 in words is "twenty-six million, one hundred thirty-nine thousand, nine hundred eighty-nine".