21420243004 has 12 divisors (see below), whose sum is σ = 37692528328. Its totient is φ = 10650949200.

The previous prime is 21420242989. The next prime is 21420243077. The reversal of 21420243004 is 40034202412.

It is a happy number.

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, 14792262 + ... + 14793709.

Almost surely, 2^21420243004 is an apocalyptic number.

It is an amenable number.

21420243004 is a deficient number, since it is larger than the sum of its proper divisors (16272285324).

21420243004 is a wasteful number, since it uses less digits than its factorization.

21420243004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29586156 (or 29586154 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21420243004 its reverse (40034202412), we get a palindrome (61454445416).

The spelling of 21420243004 in words is "twenty-one billion, four hundred twenty million, two hundred forty-three thousand, four".