21226321177 has 4 divisors (see below), whose sum is σ = 21235033636. Its totient is φ = 21217608720.

The previous prime is 21226321169. The next prime is 21226321183. The reversal of 21226321177 is 77112362212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8803881241 + 12422439936 = 93829^2 + 111456^2 .

It is a cyclic number.

It is not a de Polignac number, because 21226321177 - 2³ = 21226321169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21226321117) 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, 4352574 + ... + 4357447.

It is an arithmetic number, because the mean of its divisors is an integer number (5308758409).

Almost surely, 2^21226321177 is an apocalyptic number.

It is an amenable number.

21226321177 is a deficient number, since it is larger than the sum of its proper divisors (8712459).

21226321177 is an equidigital number, since it uses as much as digits as its factorization.

21226321177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8712458.

The product of its digits is 14112, while the sum is 34.

Adding to 21226321177 its reverse (77112362212), we get a palindrome (98338683389).

The spelling of 21226321177 in words is "twenty-one billion, two hundred twenty-six million, three hundred twenty-one thousand, one hundred seventy-seven".