21007004426 has 8 divisors (see below), whose sum is σ = 31518972480. Its totient is φ = 10500680268.

The previous prime is 21007004413. The next prime is 21007004429. The reversal of 21007004426 is 62440070012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21007004395 and 21007004404.

It is not an unprimeable number, because it can be changed into a prime (21007004429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1401656 + ... + 1416563.

It is an arithmetic number, because the mean of its divisors is an integer number (3939871560).

Almost surely, 2^21007004426 is an apocalyptic number.

21007004426 is a deficient number, since it is larger than the sum of its proper divisors (10511968054).

21007004426 is a wasteful number, since it uses less digits than its factorization.

21007004426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2821948.

The product of its (nonzero) digits is 2688, while the sum is 26.

Adding to 21007004426 its reverse (62440070012), we get a palindrome (83447074438).

The spelling of 21007004426 in words is "twenty-one billion, seven million, four thousand, four hundred twenty-six".