212405531 has 16 divisors (see below), whose sum is σ = 244944000. Its totient is φ = 182443008.

The previous prime is 212405527. The next prime is 212405563. The reversal of 212405531 is 135504212.

It is a cyclic number.

It is not a de Polignac number, because 212405531 - 2² = 212405527 is a prime.

It is a super-2 number, since 2×212405531² = 90232219198783922, 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 = 212405497 and 212405506.

It is not an unprimeable number, because it can be changed into a prime (212405231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14270 + ... + 25068.

It is an arithmetic number, because the mean of its divisors is an integer number (15309000).

Almost surely, 2^212405531 is an apocalyptic number.

212405531 is a deficient number, since it is larger than the sum of its proper divisors (32538469).

212405531 is a wasteful number, since it uses less digits than its factorization.

212405531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10918.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 212405531 is about 14574.1391169427. The cubic root of 212405531 is about 596.6531537084.

Adding to 212405531 its reverse (135504212), we get a palindrome (347909743).

The spelling of 212405531 in words is "two hundred twelve million, four hundred five thousand, five hundred thirty-one".