212531403 has 16 divisors (see below), whose sum is σ = 325491200. Its totient is φ = 120833856.

The previous prime is 212531383. The next prime is 212531447. The reversal of 212531403 is 304135212.

It is not a de Polignac number, because 212531403 - 2⁸ = 212531147 is a prime.

It is a super-2 number, since 2×212531403² = 90339194522296818, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212531403.

It is not an unprimeable number, because it can be changed into a prime (212531483) 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, 21250 + ... + 29607.

It is an arithmetic number, because the mean of its divisors is an integer number (20343200).

Almost surely, 2^212531403 is an apocalyptic number.

212531403 is a deficient number, since it is larger than the sum of its proper divisors (112959797).

212531403 is a wasteful number, since it uses less digits than its factorization.

212531403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51066.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 212531403 is about 14578.4568113364. The cubic root of 212531403 is about 596.7709897728.

Adding to 212531403 its reverse (304135212), we get a palindrome (516666615).

The spelling of 212531403 in words is "two hundred twelve million, five hundred thirty-one thousand, four hundred three".