21140400040 has 16 divisors (see below), whose sum is σ = 47565900180. Its totient is φ = 8456160000.

The previous prime is 21140400037. The next prime is 21140400097. The reversal of 21140400040 is 4000404112.

It can be written as a sum of positive squares in 2 ways, for example, as 20794216804 + 346183236 = 144202^2 + 18606^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21140399987 and 21140400023.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264254961 + ... + 264255040.

Almost surely, 2^21140400040 is an apocalyptic number.

21140400040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21140400040 is an abundant number, since it is smaller than the sum of its proper divisors (26425500140).

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

21140400040 is a wasteful number, since it uses less digits than its factorization.

21140400040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528510012 (or 528510008 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21140400040 its reverse (4000404112), we get a palindrome (25140804152).

The spelling of 21140400040 in words is "twenty-one billion, one hundred forty million, four hundred thousand, forty".