21506205472373 has 8 divisors (see below), whose sum is σ = 22129290295200. Its totient is φ = 20888708854608.

The previous prime is 21506205472333. The next prime is 21506205472391. The reversal of 21506205472373 is 37327450260512.

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 21506205472373 - 2¹⁴ = 21506205455989 is a prime.

It is a super-2 number, since 2×21506205472373² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506205472303) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1397043458 + ... + 1397058851.

It is an arithmetic number, because the mean of its divisors is an integer number (2766161286900).

Almost surely, 2^{21506205472373} is an apocalyptic number.

It is an amenable number.

21506205472373 is a deficient number, since it is larger than the sum of its proper divisors (623084822827).

21506205472373 is a wasteful number, since it uses less digits than its factorization.

21506205472373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2794102531.

The product of its (nonzero) digits is 2116800, while the sum is 47.

The spelling of 21506205472373 in words is "twenty-one trillion, five hundred six billion, two hundred five million, four hundred seventy-two thousand, three hundred seventy-three".