21777204449 has 32 divisors (see below), whose sum is σ = 29273481216. Its totient is φ = 15645625920.

The previous prime is 21777204439. The next prime is 21777204451. The reversal of 21777204449 is 94440277712.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21777204449 is a prime.

It is a super-2 number, since 2×21777204449² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21777204439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 875624 + ... + 900150.

It is an arithmetic number, because the mean of its divisors is an integer number (914796288).

Almost surely, 2^21777204449 is an apocalyptic number.

It is an amenable number.

21777204449 is a deficient number, since it is larger than the sum of its proper divisors (7496276767).

21777204449 is a wasteful number, since it uses less digits than its factorization.

21777204449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25445.

The product of its (nonzero) digits is 790272, while the sum is 47.

The spelling of 21777204449 in words is "twenty-one billion, seven hundred seventy-seven million, two hundred four thousand, four hundred forty-nine".