21175426947 has 4 divisors (see below), whose sum is σ = 28233902600. Its totient is φ = 14116951296.

The previous prime is 21175426931. The next prime is 21175426949. The reversal of 21175426947 is 74962457112.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21175426947 - 2⁴ = 21175426931 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21175426896 and 21175426905.

It is not an unprimeable number, because it can be changed into a prime (21175426949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3529237822 + ... + 3529237827.

It is an arithmetic number, because the mean of its divisors is an integer number (7058475650).

Almost surely, 2^21175426947 is an apocalyptic number.

21175426947 is a deficient number, since it is larger than the sum of its proper divisors (7058475653).

21175426947 is an equidigital number, since it uses as much as digits as its factorization.

21175426947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7058475652.

The product of its digits is 846720, while the sum is 48.

The spelling of 21175426947 in words is "twenty-one billion, one hundred seventy-five million, four hundred twenty-six thousand, nine hundred forty-seven".