213631031 has 2 divisors, whose sum is σ = 213631032. Its totient is φ = 213631030.

The previous prime is 213631021. The next prime is 213631037. The reversal of 213631031 is 130136312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 213631031 - 2²² = 209436727 is a prime.

It is a super-2 number, since 2×213631031² = 91276434812245922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 213630994 and 213631012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213631037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106815515 + 106815516.

It is an arithmetic number, because the mean of its divisors is an integer number (106815516).

Almost surely, 2^213631031 is an apocalyptic number.

213631031 is a deficient number, since it is larger than the sum of its proper divisors (1).

213631031 is an equidigital number, since it uses as much as digits as its factorization.

213631031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 213631031 is about 14616.1222969706. The cubic root of 213631031 is about 597.7984419691.

Adding to 213631031 its reverse (130136312), we get a palindrome (343767343).

The spelling of 213631031 in words is "two hundred thirteen million, six hundred thirty-one thousand, thirty-one".