21771132043 has 4 divisors (see below), whose sum is σ = 21771452808. Its totient is φ = 21770811280.

The previous prime is 21771131999. The next prime is 21771132077. The reversal of 21771132043 is 34023117712.

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

It is a cyclic number.

It is not a de Polignac number, because 21771132043 - 2⁹ = 21771131531 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21771131996 and 21771132014.

It is not an unprimeable number, because it can be changed into a prime (21771132343) 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, 14098 + ... + 209143.

It is an arithmetic number, because the mean of its divisors is an integer number (5442863202).

Almost surely, 2^21771132043 is an apocalyptic number.

21771132043 is a deficient number, since it is larger than the sum of its proper divisors (320765).

21771132043 is an equidigital number, since it uses as much as digits as its factorization.

21771132043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320764.

The product of its (nonzero) digits is 7056, while the sum is 31.

Adding to 21771132043 its reverse (34023117712), we get a palindrome (55794249755).

The spelling of 21771132043 in words is "twenty-one billion, seven hundred seventy-one million, one hundred thirty-two thousand, forty-three".