21353204434 has 16 divisors (see below), whose sum is σ = 32099797440. Its totient is φ = 10653294960.

The previous prime is 21353204429. The next prime is 21353204447. The reversal of 21353204434 is 43440235312.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21353204396 and 21353204405.

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, 2352597 + ... + 2361655.

It is an arithmetic number, because the mean of its divisors is an integer number (2006237340).

Almost surely, 2^21353204434 is an apocalyptic number.

21353204434 is a deficient number, since it is larger than the sum of its proper divisors (10746593006).

21353204434 is a wasteful number, since it uses less digits than its factorization.

21353204434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11505.

The product of its (nonzero) digits is 34560, while the sum is 31.

Adding to 21353204434 its reverse (43440235312), we get a palindrome (64793439746).

The spelling of 21353204434 in words is "twenty-one billion, three hundred fifty-three million, two hundred four thousand, four hundred thirty-four".