213315631 has 2 divisors, whose sum is σ = 213315632. Its totient is φ = 213315630.

The previous prime is 213315617. The next prime is 213315653. The reversal of 213315631 is 136513312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 213315631 - 2⁹ = 213315119 is a prime.

It is a super-2 number, since 2×213315631² = 91007116857856322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 213315596 and 213315605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213315601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106657815 + 106657816.

It is an arithmetic number, because the mean of its divisors is an integer number (106657816).

Almost surely, 2^213315631 is an apocalyptic number.

213315631 is a deficient number, since it is larger than the sum of its proper divisors (1).

213315631 is an equidigital number, since it uses as much as digits as its factorization.

213315631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620, while the sum is 25.

The square root of 213315631 is about 14605.3288562771. The cubic root of 213315631 is about 597.5041050587.

Adding to 213315631 its reverse (136513312), we get a palindrome (349828943).

It can be divided in two parts, 21331 and 5631, that added together give a palindrome (26962).

The spelling of 213315631 in words is "two hundred thirteen million, three hundred fifteen thousand, six hundred thirty-one".