21879552818 has 8 divisors (see below), whose sum is σ = 32821135212. Its totient is φ = 10939174416.

The previous prime is 21879552689. The next prime is 21879552839. The reversal of 21879552818 is 81825597812.

It can be written as a sum of positive squares in 2 ways, for example, as 21739438249 + 140114569 = 147443^2 + 11837^2 .

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

It is a super-2 number, since 2×21879552818² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254105 + ... + 329132.

Almost surely, 2^21879552818 is an apocalyptic number.

21879552818 is a deficient number, since it is larger than the sum of its proper divisors (10941582394).

21879552818 is a wasteful number, since it uses less digits than its factorization.

21879552818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 601996.

The product of its digits is 3225600, while the sum is 56.

The spelling of 21879552818 in words is "twenty-one billion, eight hundred seventy-nine million, five hundred fifty-two thousand, eight hundred eighteen".