21421422433 has 4 divisors (see below), whose sum is σ = 21424939668. Its totient is φ = 21417905200.

The previous prime is 21421422413. The next prime is 21421422443. The reversal of 21421422433 is 33422412412.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7276601809 + 14144820624 = 85303^2 + 118932^2 .

It is a cyclic number.

It is not a de Polignac number, because 21421422433 - 2⁵ = 21421422401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21421422403) 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, 1749466 + ... + 1761667.

It is an arithmetic number, because the mean of its divisors is an integer number (5356234917).

Almost surely, 2^21421422433 is an apocalyptic number.

It is an amenable number.

21421422433 is a deficient number, since it is larger than the sum of its proper divisors (3517235).

21421422433 is an equidigital number, since it uses as much as digits as its factorization.

21421422433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3517234.

The product of its digits is 9216, while the sum is 28.

Adding to 21421422433 its reverse (33422412412), we get a palindrome (54843834845).

The spelling of 21421422433 in words is "twenty-one billion, four hundred twenty-one million, four hundred twenty-two thousand, four hundred thirty-three".