212421681 has 24 divisors (see below), whose sum is σ = 326177280. Its totient is φ = 132752256.

The previous prime is 212421667. The next prime is 212421689. The reversal of 212421681 is 186124212.

It is not a de Polignac number, because 212421681 - 2⁶ = 212421617 is a prime.

It is a super-2 number, since 2×212421681² = 90245941117731522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (212421689) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37600 + ... + 42878.

It is an arithmetic number, because the mean of its divisors is an integer number (13590720).

Almost surely, 2^212421681 is an apocalyptic number.

It is an amenable number.

212421681 is a deficient number, since it is larger than the sum of its proper divisors (113755599).

212421681 is a wasteful number, since it uses less digits than its factorization.

212421681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5565 (or 5562 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 212421681 is about 14574.6931700122. The cubic root of 212421681 is about 596.6682752610.

Adding to 212421681 its reverse (186124212), we get a palindrome (398545893).

The spelling of 212421681 in words is "two hundred twelve million, four hundred twenty-one thousand, six hundred eighty-one".