212555421 has 40 divisors (see below), whose sum is σ = 345636984. Its totient is φ = 129392640.

The previous prime is 212555401. The next prime is 212555449. The reversal of 212555421 is 124555212.

It can be written as a sum of positive squares in 4 ways, for example, as 2595321 + 209960100 = 1611^2 + 14490^2 .

It is not a de Polignac number, because 212555421 - 2⁵ = 212555389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212555401) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 101101 + ... + 103181.

Almost surely, 2^212555421 is an apocalyptic number.

It is an amenable number.

212555421 is a deficient number, since it is larger than the sum of its proper divisors (133081563).

212555421 is a wasteful number, since it uses less digits than its factorization.

212555421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2203 (or 2194 counting only the distinct ones).

The product of its digits is 4000, while the sum is 27.

The square root of 212555421 is about 14579.2805378043. The cubic root of 212555421 is about 596.7934691265.

The spelling of 212555421 in words is "two hundred twelve million, five hundred fifty-five thousand, four hundred twenty-one".