21420231212 has 12 divisors (see below), whose sum is σ = 37508038680. Its totient is φ = 10703648736.

The previous prime is 21420231199. The next prime is 21420231241. The reversal of 21420231212 is 21213202412.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1609262 + ... + 1622517.

It is an arithmetic number, because the mean of its divisors is an integer number (3125669890).

Almost surely, 2^21420231212 is an apocalyptic number.

It is an amenable number.

21420231212 is a deficient number, since it is larger than the sum of its proper divisors (16087807468).

21420231212 is a wasteful number, since it uses less digits than its factorization.

21420231212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3233440 (or 3233438 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21420231212 its reverse (21213202412), we get a palindrome (42633433624).

The spelling of 21420231212 in words is "twenty-one billion, four hundred twenty million, two hundred thirty-one thousand, two hundred twelve".