21777774511 has 2 divisors, whose sum is σ = 21777774512. Its totient is φ = 21777774510.

The previous prime is 21777774437. The next prime is 21777774533. The reversal of 21777774511 is 11547777712.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21777774511 - 2⁹ = 21777773999 is a prime.

It is a super-2 number, since 2×21777774511² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21777774211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10888887255 + 10888887256.

It is an arithmetic number, because the mean of its divisors is an integer number (10888887256).

Almost surely, 2^21777774511 is an apocalyptic number.

21777774511 is a deficient number, since it is larger than the sum of its proper divisors (1).

21777774511 is an equidigital number, since it uses as much as digits as its factorization.

21777774511 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672280, while the sum is 49.

The spelling of 21777774511 in words is "twenty-one billion, seven hundred seventy-seven million, seven hundred seventy-four thousand, five hundred eleven".