21043423234 has 16 divisors (see below), whose sum is σ = 31984801920. Its totient is φ = 10381990320.

The previous prime is 21043423169. The next prime is 21043423243. The reversal of 21043423234 is 43232434012.

It is a super-2 number, since 2×21043423234² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 215037 + ... + 297199.

It is an arithmetic number, because the mean of its divisors is an integer number (1999050120).

Almost surely, 2^21043423234 is an apocalyptic number.

21043423234 is a deficient number, since it is larger than the sum of its proper divisors (10941378686).

21043423234 is a wasteful number, since it uses less digits than its factorization.

21043423234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83865.

The product of its (nonzero) digits is 13824, while the sum is 28.

Adding to 21043423234 its reverse (43232434012), we get a palindrome (64275857246).

The spelling of 21043423234 in words is "twenty-one billion, forty-three million, four hundred twenty-three thousand, two hundred thirty-four".