201221012142 has 72 divisors (see below), whose sum is σ = 464082387912. Its totient is φ = 62998790400.

The previous prime is 201221012141. The next prime is 201221012147. The reversal of 201221012142 is 241210122102.

It is a super-2 number, since 2×201221012142² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221012141) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2514792 + ... + 2593572.

It is an arithmetic number, because the mean of its divisors is an integer number (6445588721).

Almost surely, 2^201221012142 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 201221012142, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (232041193956).

201221012142 is an abundant number, since it is smaller than the sum of its proper divisors (262861375770).

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

201221012142 is a wasteful number, since it uses less digits than its factorization.

201221012142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79314 (or 79294 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 201221012142 its reverse (241210122102), we get a palindrome (442431134244).

The spelling of 201221012142 in words is "two hundred one billion, two hundred twenty-one million, twelve thousand, one hundred forty-two".