28626391 has 2 divisors, whose sum is σ = 28626392. Its totient is φ = 28626390.

The previous prime is 28626383. The next prime is 28626401. The reversal of 28626391 is 19362682.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28626391 - 2³ = 28626383 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28626391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28626341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14313195 + 14313196.

It is an arithmetic number, because the mean of its divisors is an integer number (14313196).

Almost surely, 2^28626391 is an apocalyptic number.

28626391 is a deficient number, since it is larger than the sum of its proper divisors (1).

28626391 is an equidigital number, since it uses as much as digits as its factorization.

28626391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 28626391 is about 5350.3636325020. The cubic root of 28626391 is about 305.9066135351.

The spelling of 28626391 in words is "twenty-eight million, six hundred twenty-six thousand, three hundred ninety-one".