212215421 has 8 divisors (see below), whose sum is σ = 231717024. Its totient is φ = 192748720.

The previous prime is 212215361. The next prime is 212215433. The reversal of 212215421 is 124512212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212215421 - 2¹⁰ = 212214397 is a prime.

It is a Curzon number.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 212215393 and 212215402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212211421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4931 + ... + 21183.

It is an arithmetic number, because the mean of its divisors is an integer number (28964628).

Almost surely, 2^212215421 is an apocalyptic number.

It is an amenable number.

212215421 is a deficient number, since it is larger than the sum of its proper divisors (19501603).

212215421 is a wasteful number, since it uses less digits than its factorization.

212215421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17451.

The product of its digits is 320, while the sum is 20.

The square root of 212215421 is about 14567.6154877866. The cubic root of 212215421 is about 596.4750924491.

Adding to 212215421 its reverse (124512212), we get a palindrome (336727633).

The spelling of 212215421 in words is "two hundred twelve million, two hundred fifteen thousand, four hundred twenty-one".