21204306434 has 8 divisors (see below), whose sum is σ = 31938437388. Its totient is φ = 10558160640.

The previous prime is 21204306433. The next prime is 21204306469. The reversal of 21204306434 is 43460340212.

It can be written as a sum of positive squares in 2 ways, for example, as 21053139409 + 151167025 = 145097^2 + 12295^2 .

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

It is a super-2 number, since 2×21204306434² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21204306397 and 21204306406.

It is not an unprimeable number, because it can be changed into a prime (21204306433) 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, 21995687 + ... + 21996650.

Almost surely, 2^21204306434 is an apocalyptic number.

21204306434 is a deficient number, since it is larger than the sum of its proper divisors (10734130954).

21204306434 is a wasteful number, since it uses less digits than its factorization.

21204306434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43992580.

The product of its (nonzero) digits is 13824, while the sum is 29.

Adding to 21204306434 its reverse (43460340212), we get a palindrome (64664646646).

The spelling of 21204306434 in words is "twenty-one billion, two hundred four million, three hundred six thousand, four hundred thirty-four".