21820000040 has 32 divisors (see below), whose sum is σ = 50139578880. Its totient is φ = 8542297152.

The previous prime is 21820000009. The next prime is 21820000049. The reversal of 21820000040 is 4000002812.

It is a super-2 number, since 2×21820000040² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21819999973 and 21820000018.

It is not an unprimeable number, because it can be changed into a prime (21820000049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5801312 + ... + 5805071.

It is an arithmetic number, because the mean of its divisors is an integer number (1566861840).

Almost surely, 2^21820000040 is an apocalyptic number.

21820000040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21820000040 is an abundant number, since it is smaller than the sum of its proper divisors (28319578840).

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

21820000040 is a wasteful number, since it uses less digits than its factorization.

21820000040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11606441 (or 11606437 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21820000040 its reverse (4000002812), we get a palindrome (25820002852).

The spelling of 21820000040 in words is "twenty-one billion, eight hundred twenty million, forty", and thus it is an aban number.