21866423040 has 1296 divisors, whose sum is σ = 99745761024. Its totient is φ = 4488929280.

The previous prime is 21866423039. The next prime is 21866423069. The reversal of 21866423040 is 4032466812.

21866423040 is a `hidden beast` number, since 2 + 1 + 8 + 6 + 642 + 3 + 0 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1296).

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

It is a junction number, because it is equal to n+sod(n) for n = 21866422986 and 21866423004.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 263450839 + ... + 263450921.

Almost surely, 2^21866423040 is an apocalyptic number.

21866423040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21866423040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49872880512).

21866423040 is an abundant number, since it is smaller than the sum of its proper divisors (77879337984).

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

21866423040 is an equidigital number, since it uses as much as digits as its factorization.

21866423040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

Adding to 21866423040 its reverse (4032466812), we get a palindrome (25898889852).

The spelling of 21866423040 in words is "twenty-one billion, eight hundred sixty-six million, four hundred twenty-three thousand, forty".