221121012020 has 12 divisors (see below), whose sum is σ = 464354125284. Its totient is φ = 88448404800.

The previous prime is 221121012011. The next prime is 221121012023. The reversal of 221121012020 is 20210121122.

It can be written as a sum of positive squares in 2 ways, for example, as 173077632676 + 48043379344 = 416026^2 + 219188^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221121011986 and 221121012004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121012023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5528025281 + ... + 5528025320.

It is an arithmetic number, because the mean of its divisors is an integer number (38696177107).

Almost surely, 2^221121012020 is an apocalyptic number.

221121012020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221121012020 is an abundant number, since it is smaller than the sum of its proper divisors (243233113264).

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

221121012020 is a wasteful number, since it uses less digits than its factorization.

221121012020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11056050610 (or 11056050608 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 221121012020 its reverse (20210121122), we get a palindrome (241331133142).

The spelling of 221121012020 in words is "two hundred twenty-one billion, one hundred twenty-one million, twelve thousand, twenty".