213211531 has 16 divisors (see below), whose sum is σ = 234394720. Its totient is φ = 192741120.

The previous prime is 213211519. The next prime is 213211549. The reversal of 213211531 is 135112312.

It is not a de Polignac number, because 213211531 - 2¹⁹ = 212687243 is a prime.

It is a super-2 number, since 2×213211531² = 90918313902727922, 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 = 213211499 and 213211508.

It is not an unprimeable number, because it can be changed into a prime (213211511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 247780 + ... + 248638.

It is an arithmetic number, because the mean of its divisors is an integer number (14649670).

Almost surely, 2^213211531 is an apocalyptic number.

213211531 is a deficient number, since it is larger than the sum of its proper divisors (21183189).

213211531 is a wasteful number, since it uses less digits than its factorization.

213211531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1246.

The product of its digits is 180, while the sum is 19.

The square root of 213211531 is about 14601.7646536301. The cubic root of 213211531 is about 597.4068934012.

Adding to 213211531 its reverse (135112312), we get a palindrome (348323843).

The spelling of 213211531 in words is "two hundred thirteen million, two hundred eleven thousand, five hundred thirty-one".