21040420312 has 16 divisors (see below), whose sum is σ = 39702069360. Its totient is φ = 10453201824.

The previous prime is 21040420301. The next prime is 21040420321. The reversal of 21040420312 is 21302404012.

It is a self number, because there is not a number n which added to its sum of digits gives 21040420312.

It is a congruent number.

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, 8374708 + ... + 8377219.

It is an arithmetic number, because the mean of its divisors is an integer number (2481379335).

Almost surely, 2^21040420312 is an apocalyptic number.

It is an amenable number.

21040420312 is a deficient number, since it is larger than the sum of its proper divisors (18661649048).

21040420312 is a wasteful number, since it uses less digits than its factorization.

21040420312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16752090 (or 16752086 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 21040420312 its reverse (21302404012), we get a palindrome (42342824324).

The spelling of 21040420312 in words is "twenty-one billion, forty million, four hundred twenty thousand, three hundred twelve".