21980220040 has 32 divisors (see below), whose sum is σ = 52364643480. Its totient is φ = 8274906112.

The previous prime is 21980220013. The next prime is 21980220047. The reversal of 21980220040 is 4002208912.

It can be written as a sum of positive squares in 4 ways, for example, as 17504877636 + 4475342404 = 132306^2 + 66898^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21980219990 and 21980220008.

It is not an unprimeable number, because it can be changed into a prime (21980220047) 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, 16161247 + ... + 16162606.

Almost surely, 2^21980220040 is an apocalyptic number.

21980220040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21980220040 is an abundant number, since it is smaller than the sum of its proper divisors (30384423440).

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

21980220040 is a wasteful number, since it uses less digits than its factorization.

21980220040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32323881 (or 32323877 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

Adding to 21980220040 its reverse (4002208912), we get a palindrome (25982428952).

The spelling of 21980220040 in words is "twenty-one billion, nine hundred eighty million, two hundred twenty thousand, forty".