21420242000 has 40 divisors (see below), whose sum is σ = 51794149992. Its totient is φ = 8568096000.

The previous prime is 21420241967. The next prime is 21420242003. The reversal of 21420242000 is 24202412.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 31764496 + 21388477504 = 5636^2 + 146248^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 21420242000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420242003) 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, 5353061 + ... + 5357060.

Almost surely, 2^21420242000 is an apocalyptic number.

21420242000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21420242000 is an abundant number, since it is smaller than the sum of its proper divisors (30373907992).

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

21420242000 is a wasteful number, since it uses less digits than its factorization.

21420242000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10710144 (or 10710128 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 17.

Adding to 21420242000 its reverse (24202412), we get a palindrome (21444444412).

The spelling of 21420242000 in words is "twenty-one billion, four hundred twenty million, two hundred forty-two thousand".