221137812 has 36 divisors (see below), whose sum is σ = 638843296. Its totient is φ = 63182160.

The previous prime is 221137799. The next prime is 221137843. The reversal of 221137812 is 218731122.

221137812 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×221137812² = 97803863792294688, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 438514 + ... + 439017.

Almost surely, 2^221137812 is an apocalyptic number.

It is an amenable number.

221137812 is an abundant number, since it is smaller than the sum of its proper divisors (417705484).

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

221137812 is a wasteful number, since it uses less digits than its factorization.

221137812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 877548 (or 877543 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 221137812 is about 14870.7031441018. The cubic root of 221137812 is about 604.7200052194.

Adding to 221137812 its reverse (218731122), we get a palindrome (439868934).

The spelling of 221137812 in words is "two hundred twenty-one million, one hundred thirty-seven thousand, eight hundred twelve".