253721197 has 4 divisors (see below), whose sum is σ = 254637436. Its totient is φ = 252804960.

The previous prime is 253721189. The next prime is 253721201. The reversal of 253721197 is 791127352.

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 168454441 + 85266756 = 12979^2 + 9234^2 .

It is a cyclic number.

It is not a de Polignac number, because 253721197 - 2³ = 253721189 is a prime.

It is a super-2 number, since 2×253721197² = 128748891614225618, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253721297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 457704 + ... + 458257.

It is an arithmetic number, because the mean of its divisors is an integer number (63659359).

Almost surely, 2^253721197 is an apocalyptic number.

It is an amenable number.

253721197 is a deficient number, since it is larger than the sum of its proper divisors (916239).

253721197 is an equidigital number, since it uses as much as digits as its factorization.

253721197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916238.

The product of its digits is 26460, while the sum is 37.

The square root of 253721197 is about 15928.6282209109. The cubic root of 253721197 is about 633.0707535380.

It can be divided in two parts, 25372119 and 7, that added together give a triangular number (25372126 = T₇₁₂₃).

The spelling of 253721197 in words is "two hundred fifty-three million, seven hundred twenty-one thousand, one hundred ninety-seven".