857640253 has 2 divisors, whose sum is σ = 857640254. Its totient is φ = 857640252.

The previous prime is 857640239. The next prime is 857640257. The reversal of 857640253 is 352046758.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 665485209 + 192155044 = 25797^2 + 13862^2 .

It is a cyclic number.

It is not a de Polignac number, because 857640253 - 2¹⁷ = 857509181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (857640257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428820126 + 428820127.

It is an arithmetic number, because the mean of its divisors is an integer number (428820127).

Almost surely, 2^857640253 is an apocalyptic number.

It is an amenable number.

857640253 is a deficient number, since it is larger than the sum of its proper divisors (1).

857640253 is an equidigital number, since it uses as much as digits as its factorization.

857640253 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 201600, while the sum is 40.

The square root of 857640253 is about 29285.4956078944. The cubic root of 857640253 is about 950.0979596123.

The spelling of 857640253 in words is "eight hundred fifty-seven million, six hundred forty thousand, two hundred fifty-three".