201121020 has 72 divisors (see below), whose sum is σ = 611222976. Its totient is φ = 53530752.

The previous prime is 201121013. The next prime is 201121021. The reversal of 201121020 is 20121102.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 201120993 and 201121011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201121021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 181789 + ... + 182891.

It is an arithmetic number, because the mean of its divisors is an integer number (8489208).

Almost surely, 2^201121020 is an apocalyptic number.

201121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201121020 is an abundant number, since it is smaller than the sum of its proper divisors (410101956).

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

201121020 is a wasteful number, since it uses less digits than its factorization.

201121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2131 (or 2126 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 201121020 is about 14181.7142828362. The cubic root of 201121020 is about 585.8941400021.

Adding to 201121020 its reverse (20121102), we get a palindrome (221242122).

The spelling of 201121020 in words is "two hundred one million, one hundred twenty-one thousand, twenty".