28400917 has 2 divisors, whose sum is σ = 28400918. Its totient is φ = 28400916.

The previous prime is 28400893. The next prime is 28400927. The reversal of 28400917 is 71900482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26946481 + 1454436 = 5191^2 + 1206^2 .

It is a cyclic number.

It is not a de Polignac number, because 28400917 - 2⁷ = 28400789 is a prime.

It is a super-2 number, since 2×28400917² = 1613224172881778, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28400927) 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 as a sum of consecutive naturals, namely, 14200458 + 14200459.

It is an arithmetic number, because the mean of its divisors is an integer number (14200459).

Almost surely, 2^28400917 is an apocalyptic number.

It is an amenable number.

28400917 is a deficient number, since it is larger than the sum of its proper divisors (1).

28400917 is an equidigital number, since it uses as much as digits as its factorization.

28400917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 28400917 is about 5329.2510730871. The cubic root of 28400917 is about 305.1013440879.

The spelling of 28400917 in words is "twenty-eight million, four hundred thousand, nine hundred seventeen".