213440031 has 18 divisors (see below), whose sum is σ = 358638072. Its totient is φ = 121965480.

The previous prime is 213440027. The next prime is 213440033. The reversal of 213440031 is 130044312.

It is not a de Polignac number, because 213440031 - 2² = 213440027 is a prime.

It is a super-2 number, since 2×213440031² = 91113293666561922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 213439986 and 213440013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213440033) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 241555 + ... + 242436.

Almost surely, 2^213440031 is an apocalyptic number.

213440031 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

213440031 is a deficient number, since it is larger than the sum of its proper divisors (145198041).

213440031 is a wasteful number, since it uses less digits than its factorization.

213440031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484011 (or 484001 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 213440031 is about 14609.5869551470. The cubic root of 213440031 is about 597.6202319860.

Adding to 213440031 its reverse (130044312), we get a palindrome (343484343).

The spelling of 213440031 in words is "two hundred thirteen million, four hundred forty thousand, thirty-one".