21253773829 has 4 divisors (see below), whose sum is σ = 22177850976. Its totient is φ = 20329696684.

The previous prime is 21253773811. The next prime is 21253773839. The reversal of 21253773829 is 92837735212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21253773829 - 2¹⁹ = 21253249541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253773839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 462038539 + ... + 462038584.

It is an arithmetic number, because the mean of its divisors is an integer number (5544462744).

Almost surely, 2^21253773829 is an apocalyptic number.

It is an amenable number.

21253773829 is a deficient number, since it is larger than the sum of its proper divisors (924077147).

21253773829 is an equidigital number, since it uses as much as digits as its factorization.

21253773829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 924077146.

The product of its digits is 1270080, while the sum is 49.

The spelling of 21253773829 in words is "twenty-one billion, two hundred fifty-three million, seven hundred seventy-three thousand, eight hundred twenty-nine".