28400819 has 2 divisors, whose sum is σ = 28400820. Its totient is φ = 28400818.

The previous prime is 28400789. The next prime is 28400843. The reversal of 28400819 is 91800482.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28400819 - 2¹⁶ = 28335283 is a prime.

It is a super-2 number, since 2×28400819² = 1613213039741522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28400219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14200409 + 14200410.

It is an arithmetic number, because the mean of its divisors is an integer number (14200410).

Almost surely, 2^28400819 is an apocalyptic number.

28400819 is a deficient number, since it is larger than the sum of its proper divisors (1).

28400819 is an equidigital number, since it uses as much as digits as its factorization.

28400819 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 28400819 is about 5329.2418785414. The cubic root of 28400819 is about 305.1009931607.

The spelling of 28400819 in words is "twenty-eight million, four hundred thousand, eight hundred nineteen".