28515247 has 2 divisors, whose sum is σ = 28515248. Its totient is φ = 28515246.

The previous prime is 28515217. The next prime is 28515251. The reversal of 28515247 is 74251582.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28515247 - 2⁷ = 28515119 is a prime.

It is a super-2 number, since 2×28515247² = 1626238622942018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28515217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14257623 + 14257624.

It is an arithmetic number, because the mean of its divisors is an integer number (14257624).

Almost surely, 2^28515247 is an apocalyptic number.

28515247 is a deficient number, since it is larger than the sum of its proper divisors (1).

28515247 is an equidigital number, since it uses as much as digits as its factorization.

28515247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22400, while the sum is 34.

The square root of 28515247 is about 5339.9669474633. The cubic root of 28515247 is about 305.5101986572.

The spelling of 28515247 in words is "twenty-eight million, five hundred fifteen thousand, two hundred forty-seven".