21344642633 has 4 divisors (see below), whose sum is σ = 21345041940. Its totient is φ = 21344243328.

The previous prime is 21344642569. The next prime is 21344642647. The reversal of 21344642633 is 33624644312.

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 10280337664 + 11064304969 = 101392^2 + 105187^2 .

It is a cyclic number.

It is not a de Polignac number, because 21344642633 - 2⁶ = 21344642569 is a prime.

It is a super-3 number, since 3×21344642633³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21344642233) 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, 104288 + ... + 231441.

It is an arithmetic number, because the mean of its divisors is an integer number (5336260485).

Almost surely, 2^21344642633 is an apocalyptic number.

It is an amenable number.

21344642633 is a deficient number, since it is larger than the sum of its proper divisors (399307).

21344642633 is an equidigital number, since it uses as much as digits as its factorization.

21344642633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399306.

The product of its digits is 248832, while the sum is 38.

The spelling of 21344642633 in words is "twenty-one billion, three hundred forty-four million, six hundred forty-two thousand, six hundred thirty-three".