26921557 has 16 divisors (see below), whose sum is σ = 31216752. Its totient is φ = 22993920.

The previous prime is 26921551. The next prime is 26921563. The reversal of 26921557 is 75512962.

It is an interprime number because it is at equal distance from previous prime (26921551) and next prime (26921563).

It can be written as a sum of positive squares in 8 ways, for example, as 10201636 + 16719921 = 3194^2 + 4089^2 .

It is a cyclic number.

It is not a de Polignac number, because 26921557 - 2¹¹ = 26919509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26921551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12483 + ... + 14479.

It is an arithmetic number, because the mean of its divisors is an integer number (1951047).

Almost surely, 2^26921557 is an apocalyptic number.

It is an amenable number.

26921557 is a deficient number, since it is larger than the sum of its proper divisors (4295195).

26921557 is a wasteful number, since it uses less digits than its factorization.

26921557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2088.

The product of its digits is 37800, while the sum is 37.

The square root of 26921557 is about 5188.5987511080. The cubic root of 26921557 is about 299.7091885571.

The spelling of 26921557 in words is "twenty-six million, nine hundred twenty-one thousand, five hundred fifty-seven".