21172480723 has 2 divisors, whose sum is σ = 21172480724. Its totient is φ = 21172480722.

The previous prime is 21172480687. The next prime is 21172480741. The reversal of 21172480723 is 32708427112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21172480723 - 2⁹ = 21172480211 is a prime.

It is not a weakly prime, because it can be changed into another prime (21172480753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10586240361 + 10586240362.

It is an arithmetic number, because the mean of its divisors is an integer number (10586240362).

Almost surely, 2^21172480723 is an apocalyptic number.

21172480723 is a deficient number, since it is larger than the sum of its proper divisors (1).

21172480723 is an equidigital number, since it uses as much as digits as its factorization.

21172480723 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37632, while the sum is 37.

The spelling of 21172480723 in words is "twenty-one billion, one hundred seventy-two million, four hundred eighty thousand, seven hundred twenty-three".