253021997 has 4 divisors (see below), whose sum is σ = 253067580. Its totient is φ = 252976416.

The previous prime is 253021991. The next prime is 253022017. The reversal of 253021997 is 799120352.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21799561 + 231222436 = 4669^2 + 15206^2 .

It is a cyclic number.

It is not a de Polignac number, because 253021997 - 2⁴ = 253021981 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 253021997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253021991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13088 + ... + 26025.

It is an arithmetic number, because the mean of its divisors is an integer number (63266895).

Almost surely, 2^253021997 is an apocalyptic number.

It is an amenable number.

253021997 is a deficient number, since it is larger than the sum of its proper divisors (45583).

253021997 is an equidigital number, since it uses as much as digits as its factorization.

253021997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45582.

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 253021997 is about 15906.6651753282. The cubic root of 253021997 is about 632.4886837847.

The spelling of 253021997 in words is "two hundred fifty-three million, twenty-one thousand, nine hundred ninety-seven".