21213456024 has 32 divisors (see below), whose sum is σ = 53760132720. Its totient is φ = 6974286336.

The previous prime is 21213455971. The next prime is 21213456029. The reversal of 21213456024 is 42065431212.

It is a junction number, because it is equal to n+sod(n) for n = 21213455982 and 21213456000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213456029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6052317 + ... + 6055820.

Almost surely, 2^21213456024 is an apocalyptic number.

21213456024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21213456024 is an abundant number, since it is smaller than the sum of its proper divisors (32546676696).

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

21213456024 is a wasteful number, since it uses less digits than its factorization.

21213456024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12108219 (or 12108215 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

Adding to 21213456024 its reverse (42065431212), we get a palindrome (63278887236).

The spelling of 21213456024 in words is "twenty-one billion, two hundred thirteen million, four hundred fifty-six thousand, twenty-four".