21420304444 has 48 divisors (see below), whose sum is σ = 47375467776. Its totient is φ = 8231241600.

The previous prime is 21420304403. The next prime is 21420304489. The reversal of 21420304444 is 44440302412.

It is a super-2 number, since 2×21420304444² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 453862 + ... + 498829.

It is an arithmetic number, because the mean of its divisors is an integer number (986988912).

Almost surely, 2^21420304444 is an apocalyptic number.

It is an amenable number.

21420304444 is an abundant number, since it is smaller than the sum of its proper divisors (25955163332).

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

21420304444 is a wasteful number, since it uses less digits than its factorization.

21420304444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 952786 (or 952784 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 28.

Adding to 21420304444 its reverse (44440302412), we get a palindrome (65860606856).

The spelling of 21420304444 in words is "twenty-one billion, four hundred twenty million, three hundred four thousand, four hundred forty-four".