21966387409 has 8 divisors (see below), whose sum is σ = 22348357920. Its totient is φ = 21584738976.

The previous prime is 21966387403. The next prime is 21966387451. The reversal of 21966387409 is 90478366912.

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 21966387409 - 2¹³ = 21966379217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21966387409.

It is not an unprimeable number, because it can be changed into a prime (21966387403) 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, 59157 + ... + 217789.

It is an arithmetic number, because the mean of its divisors is an integer number (2793544740).

Almost surely, 2^21966387409 is an apocalyptic number.

It is an amenable number.

21966387409 is a deficient number, since it is larger than the sum of its proper divisors (381970511).

21966387409 is a wasteful number, since it uses less digits than its factorization.

21966387409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161039.

The product of its (nonzero) digits is 3919104, while the sum is 55.

The spelling of 21966387409 in words is "twenty-one billion, nine hundred sixty-six million, three hundred eighty-seven thousand, four hundred nine".