21244236505 has 8 divisors (see below), whose sum is σ = 25523914752. Its totient is φ = 16974835248.

The previous prime is 21244236493. The next prime is 21244236521. The reversal of 21244236505 is 50563244212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21244236505 - 2¹⁵ = 21244203737 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2564697 + ... + 2572966.

It is an arithmetic number, because the mean of its divisors is an integer number (3190489344).

Almost surely, 2^21244236505 is an apocalyptic number.

It is an amenable number.

21244236505 is a deficient number, since it is larger than the sum of its proper divisors (4279678247).

21244236505 is an equidigital number, since it uses as much as digits as its factorization.

21244236505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5138495.

The product of its (nonzero) digits is 57600, while the sum is 34.

The spelling of 21244236505 in words is "twenty-one billion, two hundred forty-four million, two hundred thirty-six thousand, five hundred five".