20121001221220 has 24 divisors (see below), whose sum is σ = 42266629863864. Its totient is φ = 8046014336256.

The previous prime is 20121001221203. The next prime is 20121001221247. The reversal of 20121001221220 is 2212210012102.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 14758136423424 + 5362864797796 = 3841632^2 + 2315786^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20121001221194 and 20121001221203.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149065369 + ... + 149200288.

It is an arithmetic number, because the mean of its divisors is an integer number (1761109577661).

Almost surely, 2^{20121001221220} is an apocalyptic number.

20121001221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121001221220 is an abundant number, since it is smaller than the sum of its proper divisors (22145628642644).

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

20121001221220 is a wasteful number, since it uses less digits than its factorization.

20121001221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298269039 (or 298269037 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20121001221220 its reverse (2212210012102), we get a palindrome (22333211233322).

The spelling of 20121001221220 in words is "twenty trillion, one hundred twenty-one billion, one million, two hundred twenty-one thousand, two hundred twenty".