28940399 has 2 divisors, whose sum is σ = 28940400. Its totient is φ = 28940398.

The previous prime is 28940393. The next prime is 28940423. The reversal of 28940399 is 99304982.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28940399 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28940393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14470199 + 14470200.

It is an arithmetic number, because the mean of its divisors is an integer number (14470200).

Almost surely, 2^28940399 is an apocalyptic number.

28940399 is a deficient number, since it is larger than the sum of its proper divisors (1).

28940399 is an equidigital number, since it uses as much as digits as its factorization.

28940399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 28940399 is about 5379.6281470005. The cubic root of 28940399 is about 307.0210633230.

The spelling of 28940399 in words is "twenty-eight million, nine hundred forty thousand, three hundred ninety-nine".