213403257 has 12 divisors (see below), whose sum is σ = 318878820. Its totient is φ = 137362848.

The previous prime is 213403249. The next prime is 213403271. The reversal of 213403257 is 752304312.

213403257 is a `hidden beast` number, since 2 + 1 + 3 + 403 + 257 = 666.

213403257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 65999376 + 147403881 = 8124^2 + 12141^2 .

It is not a de Polignac number, because 213403257 - 2³ = 213403249 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213403257.

It is not an unprimeable number, because it can be changed into a prime (213403217) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 408558 + ... + 409079.

It is an arithmetic number, because the mean of its divisors is an integer number (26573235).

Almost surely, 2^213403257 is an apocalyptic number.

It is an amenable number.

213403257 is a deficient number, since it is larger than the sum of its proper divisors (105475563).

213403257 is a wasteful number, since it uses less digits than its factorization.

213403257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817672 (or 817669 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 27.

The square root of 213403257 is about 14608.3283437907. The cubic root of 213403257 is about 597.5859082955.

Adding to 213403257 its reverse (752304312), we get a palindrome (965707569).

The spelling of 213403257 in words is "two hundred thirteen million, four hundred three thousand, two hundred fifty-seven".