21240343933 has 2 divisors, whose sum is σ = 21240343934. Its totient is φ = 21240343932.

The previous prime is 21240343931. The next prime is 21240343939. The reversal of 21240343933 is 33934304212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11292675289 + 9947668644 = 106267^2 + 99738^2 .

It is a cyclic number.

It is not a de Polignac number, because 21240343933 - 2¹ = 21240343931 is a prime.

Together with 21240343931, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21240343931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10620171966 + 10620171967.

It is an arithmetic number, because the mean of its divisors is an integer number (10620171967).

Almost surely, 2^21240343933 is an apocalyptic number.

It is an amenable number.

21240343933 is a deficient number, since it is larger than the sum of its proper divisors (1).

21240343933 is an equidigital number, since it uses as much as digits as its factorization.

21240343933 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 34.

The spelling of 21240343933 in words is "twenty-one billion, two hundred forty million, three hundred forty-three thousand, nine hundred thirty-three".