221020312 has 16 divisors (see below), whose sum is σ = 436224600. Its totient is φ = 104693760.

The previous prime is 221020279. The next prime is 221020321. The reversal of 221020312 is 213020122.

It is a junction number, because it is equal to n+sod(n) for n = 221020292 and 221020301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 726889 + ... + 727192.

Almost surely, 2^221020312 is an apocalyptic number.

It is an amenable number.

221020312 is a deficient number, since it is larger than the sum of its proper divisors (215204288).

221020312 is a wasteful number, since it uses less digits than its factorization.

221020312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1454106 (or 1454102 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 221020312 is about 14866.7518981114. The cubic root of 221020312 is about 604.6128816894.

Adding to 221020312 its reverse (213020122), we get a palindrome (434040434).

It can be divided in two parts, 2210 and 20312, that added together give a palindrome (22522).

The spelling of 221020312 in words is "two hundred twenty-one million, twenty thousand, three hundred twelve".