21033020434 has 4 divisors (see below), whose sum is σ = 31549530654. Its totient is φ = 10516510216.

The previous prime is 21033020417. The next prime is 21033020453. The reversal of 21033020434 is 43402033012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15041796025 + 5991224409 = 122645^2 + 77403^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5258255107 + ... + 5258255110.

Almost surely, 2^21033020434 is an apocalyptic number.

21033020434 is a deficient number, since it is larger than the sum of its proper divisors (10516510220).

21033020434 is a wasteful number, since it uses less digits than its factorization.

21033020434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10516510219.

The product of its (nonzero) digits is 1728, while the sum is 22.

Adding to 21033020434 its reverse (43402033012), we get a palindrome (64435053446).

The spelling of 21033020434 in words is "twenty-one billion, thirty-three million, twenty thousand, four hundred thirty-four".