21421243024 has 40 divisors (see below), whose sum is σ = 41676618240. Its totient is φ = 10666073088.

The previous prime is 21421243021. The next prime is 21421243043. The reversal of 21421243024 is 42034212412.

It is a self number, because there is not a number n which added to its sum of digits gives 21421243024.

It is not an unprimeable number, because it can be changed into a prime (21421243021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5188449 + ... + 5192575.

It is an arithmetic number, because the mean of its divisors is an integer number (1041915456).

Almost surely, 2^21421243024 is an apocalyptic number.

It is an amenable number.

21421243024 is a deficient number, since it is larger than the sum of its proper divisors (20255375216).

21421243024 is a wasteful number, since it uses less digits than its factorization.

21421243024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5407 (or 5401 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21421243024 its reverse (42034212412), we get a palindrome (63455455436).

The spelling of 21421243024 in words is "twenty-one billion, four hundred twenty-one million, two hundred forty-three thousand, twenty-four".