28457531 has 2 divisors, whose sum is σ = 28457532. Its totient is φ = 28457530.

The previous prime is 28457501. The next prime is 28457543. The reversal of 28457531 is 13575482.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28457531 - 2⁶ = 28457467 is a prime.

It is a super-2 number, since 2×28457531² = 1619662141231922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 28457491 and 28457500.

It is not a weakly prime, because it can be changed into another prime (28457501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14228765 + 14228766.

It is an arithmetic number, because the mean of its divisors is an integer number (14228766).

Almost surely, 2^28457531 is an apocalyptic number.

28457531 is a deficient number, since it is larger than the sum of its proper divisors (1).

28457531 is an equidigital number, since it uses as much as digits as its factorization.

28457531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33600, while the sum is 35.

The square root of 28457531 is about 5334.5600568369. The cubic root of 28457531 is about 305.3039378155.

The spelling of 28457531 in words is "twenty-eight million, four hundred fifty-seven thousand, five hundred thirty-one".