21786122016 has 192 divisors, whose sum is σ = 64335600000. Its totient is φ = 7172084736.

The previous prime is 21786121997. The next prime is 21786122087. The reversal of 21786122016 is 61022168712.

21786122016 is a `hidden beast` number, since 2 + 1 + 7 + 8 + 612 + 20 + 16 = 666.

It is a super-2 number, since 2×21786122016² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29480175 + ... + 29480913.

It is an arithmetic number, because the mean of its divisors is an integer number (335081250).

Almost surely, 2^21786122016 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21786122016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32167800000).

21786122016 is an abundant number, since it is smaller than the sum of its proper divisors (42549477984).

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

21786122016 is a wasteful number, since it uses less digits than its factorization.

21786122016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1136 (or 1122 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The spelling of 21786122016 in words is "twenty-one billion, seven hundred eighty-six million, one hundred twenty-two thousand, sixteen".