20131221132 has 72 divisors (see below), whose sum is σ = 57927018240. Its totient is φ = 5835133920.

The previous prime is 20131221101. The next prime is 20131221157. The reversal of 20131221132 is 23112213102.

20131221132 is a `hidden beast` number, since 201 + 312 + 21 + 132 = 666.

It is a super-2 number, since 2×20131221132² (a number of 21 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1096032 + ... + 1114247.

It is an arithmetic number, because the mean of its divisors is an integer number (804541920).

Almost surely, 2^20131221132 is an apocalyptic number.

20131221132 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

20131221132 is an abundant number, since it is smaller than the sum of its proper divisors (37795797108).

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

20131221132 is a wasteful number, since it uses less digits than its factorization.

20131221132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2210323 (or 2210318 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 20131221132 its reverse (23112213102), we get a palindrome (43243434234).

The spelling of 20131221132 in words is "twenty billion, one hundred thirty-one million, two hundred twenty-one thousand, one hundred thirty-two".