28921307 has 2 divisors, whose sum is σ = 28921308. Its totient is φ = 28921306.

The previous prime is 28921303. The next prime is 28921337. The reversal of 28921307 is 70312982.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28921307 - 2² = 28921303 is a prime.

It is not a weakly prime, because it can be changed into another prime (28921303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14460653 + 14460654.

It is an arithmetic number, because the mean of its divisors is an integer number (14460654).

Almost surely, 2^28921307 is an apocalyptic number.

28921307 is a deficient number, since it is larger than the sum of its proper divisors (1).

28921307 is an equidigital number, since it uses as much as digits as its factorization.

28921307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 28921307 is about 5377.8533821591. The cubic root of 28921307 is about 306.9535344729.

The spelling of 28921307 in words is "twenty-eight million, nine hundred twenty-one thousand, three hundred seven".