28578391 has 2 divisors, whose sum is σ = 28578392. Its totient is φ = 28578390.

The previous prime is 28578371. The next prime is 28578409. The reversal of 28578391 is 19387582.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28578391 - 2¹¹ = 28576343 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28578371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14289195 + 14289196.

It is an arithmetic number, because the mean of its divisors is an integer number (14289196).

Almost surely, 2^28578391 is an apocalyptic number.

28578391 is a deficient number, since it is larger than the sum of its proper divisors (1).

28578391 is an equidigital number, since it uses as much as digits as its factorization.

28578391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 43.

The square root of 28578391 is about 5345.8760741342. The cubic root of 28578391 is about 305.7355390874.

The spelling of 28578391 in words is "twenty-eight million, five hundred seventy-eight thousand, three hundred ninety-one".