21180244773 has 4 divisors (see below), whose sum is σ = 28240326368. Its totient is φ = 14120163180.

The previous prime is 21180244763. The next prime is 21180244823. The reversal of 21180244773 is 37744208112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21180244773 - 2¹² = 21180240677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21180244703) 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, 3530040793 + ... + 3530040798.

It is an arithmetic number, because the mean of its divisors is an integer number (7060081592).

Almost surely, 2^21180244773 is an apocalyptic number.

It is an amenable number.

21180244773 is a deficient number, since it is larger than the sum of its proper divisors (7060081595).

21180244773 is an equidigital number, since it uses as much as digits as its factorization.

21180244773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7060081594.

The product of its (nonzero) digits is 75264, while the sum is 39.

The spelling of 21180244773 in words is "twenty-one billion, one hundred eighty million, two hundred forty-four thousand, seven hundred seventy-three".