20121312421 has 24 divisors (see below), whose sum is σ = 24823946880. Its totient is φ = 16205680512.

The previous prime is 20121312413. The next prime is 20121312439. The reversal of 20121312421 is 12421312102.

It is not a de Polignac number, because 20121312421 - 2³ = 20121312413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121310421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 496116 + ... + 535138.

It is an arithmetic number, because the mean of its divisors is an integer number (1034331120).

Almost surely, 2^20121312421 is an apocalyptic number.

It is an amenable number.

20121312421 is a deficient number, since it is larger than the sum of its proper divisors (4702634459).

20121312421 is a wasteful number, since it uses less digits than its factorization.

20121312421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39673 (or 39666 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 20121312421 its reverse (12421312102), we get a palindrome (32542624523).

The spelling of 20121312421 in words is "twenty billion, one hundred twenty-one million, three hundred twelve thousand, four hundred twenty-one".