21774365521 has 8 divisors (see below), whose sum is σ = 21989223360. Its totient is φ = 21559574352.

The previous prime is 21774365461. The next prime is 21774365549. The reversal of 21774365521 is 12556347712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21774365521 - 2¹⁹ = 21773841233 is a prime.

It is a super-2 number, since 2×21774365521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21774365021) 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 in 7 ways as a sum of consecutive naturals, for example, 870690 + ... + 895348.

It is an arithmetic number, because the mean of its divisors is an integer number (2748652920).

Almost surely, 2^21774365521 is an apocalyptic number.

It is an amenable number.

21774365521 is a deficient number, since it is larger than the sum of its proper divisors (214857839).

21774365521 is a wasteful number, since it uses less digits than its factorization.

21774365521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33335.

The product of its digits is 352800, while the sum is 43.

The spelling of 21774365521 in words is "twenty-one billion, seven hundred seventy-four million, three hundred sixty-five thousand, five hundred twenty-one".