253640397 has 16 divisors (see below), whose sum is σ = 342169920. Its totient is φ = 167110272.

The previous prime is 253640383. The next prime is 253640411. The reversal of 253640397 is 793046352.

It is an interprime number because it is at equal distance from previous prime (253640383) and next prime (253640411).

It is not a de Polignac number, because 253640397 - 2⁴ = 253640381 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253640347) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 196129 + ... + 197417.

It is an arithmetic number, because the mean of its divisors is an integer number (21385620).

Almost surely, 2^253640397 is an apocalyptic number.

It is an amenable number.

253640397 is a deficient number, since it is larger than the sum of its proper divisors (88529523).

253640397 is a wasteful number, since it uses less digits than its factorization.

253640397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2012.

The product of its (nonzero) digits is 136080, while the sum is 39.

The square root of 253640397 is about 15926.0917051234. The cubic root of 253640397 is about 633.0035438758.

The spelling of 253640397 in words is "two hundred fifty-three million, six hundred forty thousand, three hundred ninety-seven".