21239242033 has 4 divisors (see below), whose sum is σ = 21530190628. Its totient is φ = 20948293440.

The previous prime is 21239242001. The next prime is 21239242039. The reversal of 21239242033 is 33024293212.

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 9788529969 + 11450712064 = 98937^2 + 107008^2 .

It is a cyclic number.

It is not a de Polignac number, because 21239242033 - 2⁵ = 21239242001 is a prime.

It is a super-2 number, since 2×21239242033² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21239241986 and 21239242004.

It is not an unprimeable number, because it can be changed into a prime (21239242039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145474188 + ... + 145474333.

It is an arithmetic number, because the mean of its divisors is an integer number (5382547657).

Almost surely, 2^21239242033 is an apocalyptic number.

It is an amenable number.

21239242033 is a deficient number, since it is larger than the sum of its proper divisors (290948595).

21239242033 is an equidigital number, since it uses as much as digits as its factorization.

21239242033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290948594.

The product of its (nonzero) digits is 15552, while the sum is 31.

The spelling of 21239242033 in words is "twenty-one billion, two hundred thirty-nine million, two hundred forty-two thousand, thirty-three".