21367173242551 has 8 divisors (see below), whose sum is σ = 21434846907600. Its totient is φ = 21299536433472.

The previous prime is 21367173242539. The next prime is 21367173242573. The reversal of 21367173242551 is 15524237176312.

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 21367173242551 - 2³³ = 21358583307959 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21367173242495 and 21367173242504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21367173242851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8052430 + ... + 10371883.

It is an arithmetic number, because the mean of its divisors is an integer number (2679355863450).

Almost surely, 2^{21367173242551} is an apocalyptic number.

21367173242551 is a deficient number, since it is larger than the sum of its proper divisors (67673665049).

21367173242551 is a wasteful number, since it uses less digits than its factorization.

21367173242551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18427985.

The product of its digits is 2116800, while the sum is 49.

The spelling of 21367173242551 in words is "twenty-one trillion, three hundred sixty-seven billion, one hundred seventy-three million, two hundred forty-two thousand, five hundred fifty-one".