21021533434 has 16 divisors (see below), whose sum is σ = 34423976160. Its totient is φ = 9548269360.

The previous prime is 21021533419. The next prime is 21021533437. The reversal of 21021533434 is 43433512012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21021533437) 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, 317764 + ... + 378175.

It is an arithmetic number, because the mean of its divisors is an integer number (2151498510).

Almost surely, 2^21021533434 is an apocalyptic number.

21021533434 is a deficient number, since it is larger than the sum of its proper divisors (13402442726).

21021533434 is a wasteful number, since it uses less digits than its factorization.

21021533434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697325.

The product of its (nonzero) digits is 8640, while the sum is 28.

It can be divided in two parts, 21021 and 533434, that added together give a palindrome (554455).

The spelling of 21021533434 in words is "twenty-one billion, twenty-one million, five hundred thirty-three thousand, four hundred thirty-four".