21669533816 has 48 divisors (see below), whose sum is σ = 48893722200. Its totient is φ = 8966698944.

The previous prime is 21669533797. The next prime is 21669533827. The reversal of 21669533816 is 61833596612.

It is a happy number.

It is a super-3 number, since 3×21669533816³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 941726 + ... + 964461.

Almost surely, 2^21669533816 is an apocalyptic number.

It is an amenable number.

21669533816 is an abundant number, since it is smaller than the sum of its proper divisors (27224188384).

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

21669533816 is a wasteful number, since it uses less digits than its factorization.

21669533816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1906236 (or 1906225 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 50.

The spelling of 21669533816 in words is "twenty-one billion, six hundred sixty-nine million, five hundred thirty-three thousand, eight hundred sixteen".