21805964319 has 8 divisors (see below), whose sum is σ = 29860419760. Its totient is φ = 14144409216.

The previous prime is 21805964309. The next prime is 21805964329. The reversal of 21805964319 is 91346950812.

It is an interprime number because it is at equal distance from previous prime (21805964309) and next prime (21805964329).

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

It is not a de Polignac number, because 21805964319 - 2¹⁶ = 21805898783 is a prime.

It is a super-2 number, since 2×21805964319² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21805964309) 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 in 7 ways as a sum of consecutive naturals, for example, 98224954 + ... + 98225175.

It is an arithmetic number, because the mean of its divisors is an integer number (3732552470).

Almost surely, 2^21805964319 is an apocalyptic number.

21805964319 is a deficient number, since it is larger than the sum of its proper divisors (8054455441).

21805964319 is a wasteful number, since it uses less digits than its factorization.

21805964319 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196450169.

The product of its (nonzero) digits is 466560, while the sum is 48.

The spelling of 21805964319 in words is "twenty-one billion, eight hundred five million, nine hundred sixty-four thousand, three hundred nineteen".