21431212002 has 24 divisors (see below), whose sum is σ = 47689275036. Its totient is φ = 6950663136.

The previous prime is 21431211943. The next prime is 21431212003. The reversal of 21431212002 is 20021213412.

It is a happy number.

21431212002 is a `hidden beast` number, since 21 + 431 + 212 + 0 + 0 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20189283921 + 1241928081 = 142089^2 + 35241^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21431212003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16088833 + ... + 16090164.

Almost surely, 2^21431212002 is an apocalyptic number.

21431212002 is an abundant number, since it is smaller than the sum of its proper divisors (26258063034).

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

21431212002 is a wasteful number, since it uses less digits than its factorization.

21431212002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32179042 (or 32179039 counting only the distinct ones).

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

Adding to 21431212002 its reverse (20021213412), we get a palindrome (41452425414).

The spelling of 21431212002 in words is "twenty-one billion, four hundred thirty-one million, two hundred twelve thousand, two".