21774365461 has 2 divisors, whose sum is σ = 21774365462. Its totient is φ = 21774365460.

The previous prime is 21774365381. The next prime is 21774365549. The reversal of 21774365461 is 16456347712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11335860900 + 10438504561 = 106470^2 + 102169^2 .

It is a cyclic number.

It is not a de Polignac number, because 21774365461 - 2¹⁵ = 21774332693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21774365861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10887182730 + 10887182731.

It is an arithmetic number, because the mean of its divisors is an integer number (10887182731).

Almost surely, 2^21774365461 is an apocalyptic number.

It is an amenable number.

21774365461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21774365461 is an equidigital number, since it uses as much as digits as its factorization.

21774365461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720, while the sum is 46.

The spelling of 21774365461 in words is "twenty-one billion, seven hundred seventy-four million, three hundred sixty-five thousand, four hundred sixty-one".