20120221221 has 32 divisors (see below), whose sum is σ = 28165294080. Its totient is φ = 12751742784.

The previous prime is 20120221213. The next prime is 20120221229. The reversal of 20120221221 is 12212202102.

It is an interprime number because it is at equal distance from previous prime (20120221213) and next prime (20120221229).

It is not a de Polignac number, because 20120221221 - 2³ = 20120221213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20120221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20120221229) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8874130 + ... + 8876396.

It is an arithmetic number, because the mean of its divisors is an integer number (880165440).

Almost surely, 2^20120221221 is an apocalyptic number.

It is an amenable number.

20120221221 is a deficient number, since it is larger than the sum of its proper divisors (8045072859).

20120221221 is a wasteful number, since it uses less digits than its factorization.

20120221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3025.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 20120221221 its reverse (12212202102), we get a palindrome (32332423323).

The spelling of 20120221221 in words is "twenty billion, one hundred twenty million, two hundred twenty-one thousand, two hundred twenty-one".