213457 has 4 divisors (see below), whose sum is σ = 215460. Its totient is φ = 211456.

The previous prime is 213449. The next prime is 213461. The reversal of 213457 is 754312.

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 40401 + 173056 = 201^2 + 416^2 .

It is a cyclic number.

It is not a de Polignac number, because 213457 - 2³ = 213449 is a prime.

It is a Duffinian number.

213457 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213407) 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, 832 + ... + 1057.

It is an arithmetic number, because the mean of its divisors is an integer number (53865).

2²¹³⁴⁵⁷ is an apocalyptic number.

It is an amenable number.

213457 is a deficient number, since it is larger than the sum of its proper divisors (2003).

213457 is a wasteful number, since it uses less digits than its factorization.

213457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2002.

The product of its digits is 840, while the sum is 22.

The square root of 213457 is about 462.0140690499. The cubic root of 213457 is about 59.7636068985.

Adding to 213457 its reverse (754312), we get a palindrome (967769).

The spelling of 213457 in words is "two hundred thirteen thousand, four hundred fifty-seven".