212421631 has 4 divisors (see below), whose sum is σ = 212753664. Its totient is φ = 212089600.

The previous prime is 212421617. The next prime is 212421667. The reversal of 212421631 is 136124212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 212421631 - 2⁹ = 212421119 is a prime.

It is a super-2 number, since 2×212421631² = 90245898633400322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212421431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 165055 + ... + 166336.

It is an arithmetic number, because the mean of its divisors is an integer number (53188416).

Almost surely, 2^212421631 is an apocalyptic number.

212421631 is a deficient number, since it is larger than the sum of its proper divisors (332033).

212421631 is an equidigital number, since it uses as much as digits as its factorization.

212421631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332032.

The product of its digits is 576, while the sum is 22.

The square root of 212421631 is about 14574.6914547101. The cubic root of 212421631 is about 596.6682284463.

Adding to 212421631 its reverse (136124212), we get a palindrome (348545843).

The spelling of 212421631 in words is "two hundred twelve million, four hundred twenty-one thousand, six hundred thirty-one".