21317743776 has 96 divisors (see below), whose sum is σ = 67715222400. Its totient is φ = 5732499456.

The previous prime is 21317743739. The next prime is 21317743781. The reversal of 21317743776 is 67734771312.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 921601 + ... + 944448.

It is an arithmetic number, because the mean of its divisors is an integer number (705366900).

Almost surely, 2^21317743776 is an apocalyptic number.

It is an amenable number.

21317743776 is an abundant number, since it is smaller than the sum of its proper divisors (46397478624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21317743776 is a wasteful number, since it uses less digits than its factorization.

21317743776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1866086 (or 1866078 counting only the distinct ones).

The product of its digits is 1037232, while the sum is 48.

The spelling of 21317743776 in words is "twenty-one billion, three hundred seventeen million, seven hundred forty-three thousand, seven hundred seventy-six".