20121220431 has 24 divisors (see below), whose sum is σ = 31965635520. Its totient is φ = 12118833216.

The previous prime is 20121220429. The next prime is 20121220459. The reversal of 20121220431 is 13402212102.

It is a happy number.

20121220431 is a `hidden beast` number, since 2 + 0 + 1 + 212 + 20 + 431 = 666.

It is not a de Polignac number, because 20121220431 - 2¹ = 20121220429 is a prime.

It is a super-2 number, since 2×20121220431² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121220411) 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, 1824036 + ... + 1835033.

It is an arithmetic number, because the mean of its divisors is an integer number (1331901480).

Almost surely, 2^20121220431 is an apocalyptic number.

20121220431 is a deficient number, since it is larger than the sum of its proper divisors (11844415089).

20121220431 is a wasteful number, since it uses less digits than its factorization.

20121220431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3659135 (or 3659132 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 20121220431 its reverse (13402212102), we get a palindrome (33523432533).

The spelling of 20121220431 in words is "twenty billion, one hundred twenty-one million, two hundred twenty thousand, four hundred thirty-one".