212721630 has 48 divisors (see below), whose sum is σ = 561172752. Its totient is φ = 51568000.

The previous prime is 212721623. The next prime is 212721637. The reversal of 212721630 is 36127212.

It is an interprime number because it is at equal distance from previous prime (212721623) and next prime (212721637).

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 212721630.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212721637) 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, 25671 + ... + 32930.

It is an arithmetic number, because the mean of its divisors is an integer number (11691099).

Almost surely, 2^212721630 is an apocalyptic number.

212721630 is an abundant number, since it is smaller than the sum of its proper divisors (348451122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

212721630 is a wasteful number, since it uses less digits than its factorization.

212721630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58633 (or 58622 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 212721630 is about 14584.9796023169. The cubic root of 212721630 is about 596.9489840219.

Adding to 212721630 its reverse (36127212), we get a palindrome (248848842).

The spelling of 212721630 in words is "two hundred twelve million, seven hundred twenty-one thousand, six hundred thirty".