253745521 has 2 divisors, whose sum is σ = 253745522. Its totient is φ = 253745520.

The previous prime is 253745491. The next prime is 253745533. The reversal of 253745521 is 125547352.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 194993296 + 58752225 = 13964^2 + 7665^2 .

It is a cyclic number.

It is not a de Polignac number, because 253745521 - 2¹³ = 253737329 is a prime.

It is a super-2 number, since 2×253745521² = 128773578855122882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (253745561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 126872760 + 126872761.

It is an arithmetic number, because the mean of its divisors is an integer number (126872761).

Almost surely, 2^253745521 is an apocalyptic number.

It is an amenable number.

253745521 is a deficient number, since it is larger than the sum of its proper divisors (1).

253745521 is an equidigital number, since it uses as much as digits as its factorization.

253745521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42000, while the sum is 34.

The square root of 253745521 is about 15929.3917335220. The cubic root of 253745521 is about 633.0909835137.

The spelling of 253745521 in words is "two hundred fifty-three million, seven hundred forty-five thousand, five hundred twenty-one".