201221121010 has 96 divisors (see below), whose sum is σ = 480433569840. Its totient is φ = 59937067008.

The previous prime is 201221121007. The next prime is 201221121019. The reversal of 201221121010 is 10121122102.

It can be written as a sum of positive squares in 8 ways, for example, as 150513737521 + 50707383489 = 387961^2 + 225183^2 .

It is a Harshad number since it is a multiple of its sum of digits (13).

It is not an unprimeable number, because it can be changed into a prime (201221121019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 820795 + ... + 1037374.

Almost surely, 2^201221121010 is an apocalyptic number.

201221121010 is an abundant number, since it is smaller than the sum of its proper divisors (279212448830).

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

201221121010 is a wasteful number, since it uses less digits than its factorization.

201221121010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1858220 (or 1858213 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 201221121010 its reverse (10121122102), we get a palindrome (211342243112).

The spelling of 201221121010 in words is "two hundred one billion, two hundred twenty-one million, one hundred twenty-one thousand, ten".