21757676518 has 4 divisors (see below), whose sum is σ = 32636514780. Its totient is φ = 10878838258.

The previous prime is 21757676401. The next prime is 21757676519. The reversal of 21757676518 is 81567675712.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21757676519) 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 as a sum of consecutive naturals, namely, 5439419128 + ... + 5439419131.

It is an arithmetic number, because the mean of its divisors is an integer number (8159128695).

Almost surely, 2^21757676518 is an apocalyptic number.

21757676518 is a deficient number, since it is larger than the sum of its proper divisors (10878838262).

21757676518 is a wasteful number, since it uses less digits than its factorization.

21757676518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10878838261.

The product of its digits is 4939200, while the sum is 55.

The spelling of 21757676518 in words is "twenty-one billion, seven hundred fifty-seven million, six hundred seventy-six thousand, five hundred eighteen".