213940831 has 4 divisors (see below), whose sum is σ = 230397832. Its totient is φ = 197483832.

The previous prime is 213940813. The next prime is 213940841. The reversal of 213940831 is 138049312.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 213940831 - 2⁵ = 213940799 is a prime.

It is a super-2 number, since 2×213940831² = 91541358337941122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213940793 and 213940802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213940841) 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, 8228481 + ... + 8228506.

It is an arithmetic number, because the mean of its divisors is an integer number (57599458).

Almost surely, 2^213940831 is an apocalyptic number.

213940831 is a deficient number, since it is larger than the sum of its proper divisors (16457001).

213940831 is a wasteful number, since it uses less digits than its factorization.

213940831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16457000.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 213940831 is about 14626.7163437321. The cubic root of 213940831 is about 598.0872709625.

The spelling of 213940831 in words is "two hundred thirteen million, nine hundred forty thousand, eight hundred thirty-one".