212136421 has 16 divisors (see below), whose sum is σ = 265559040. Its totient is φ = 165231360.

The previous prime is 212136403. The next prime is 212136437. The reversal of 212136421 is 124631212.

212136421 = T₉₈ + T₉₉ + ... + T₁₀₈₃.

It is not a de Polignac number, because 212136421 - 2⁵ = 212136389 is a prime.

It is a super-2 number, since 2×212136421² = 90003722229378482, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 212136392 and 212136401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212136401) 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, 27285 + ... + 34186.

It is an arithmetic number, because the mean of its divisors is an integer number (16597440).

Almost surely, 2^212136421 is an apocalyptic number.

It is an amenable number.

212136421 is a deficient number, since it is larger than the sum of its proper divisors (53422619).

212136421 is a wasteful number, since it uses less digits than its factorization.

212136421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61524.

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

The square root of 212136421 is about 14564.9037415288. The cubic root of 212136421 is about 596.4010680129.

Adding to 212136421 its reverse (124631212), we get a palindrome (336767633).

The spelling of 212136421 in words is "two hundred twelve million, one hundred thirty-six thousand, four hundred twenty-one".