21506205451303 has 8 divisors (see below), whose sum is σ = 22032959655168. Its totient is φ = 20980660788024.

The previous prime is 21506205451261. The next prime is 21506205451319. The reversal of 21506205451303 is 30315450260512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21506205451303 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 (21506205455303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 302349151 + ... + 302420272.

It is an arithmetic number, because the mean of its divisors is an integer number (2754119956896).

Almost surely, 2^{21506205451303} is an apocalyptic number.

21506205451303 is a deficient number, since it is larger than the sum of its proper divisors (526754203865).

21506205451303 is an equidigital number, since it uses as much as digits as its factorization.

21506205451303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 604770293.

The product of its (nonzero) digits is 108000, while the sum is 37.

The spelling of 21506205451303 in words is "twenty-one trillion, five hundred six billion, two hundred five million, four hundred fifty-one thousand, three hundred three".