21017540900040 has 64 divisors (see below), whose sum is σ = 66371181796800. Its totient is φ = 5309694542592.

The previous prime is 21017540900017. The next prime is 21017540900101. The reversal of 21017540900040 is 4000904571012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21017540899974 and 21017540900010.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4609107567 + ... + 4609112126.

It is an arithmetic number, because the mean of its divisors is an integer number (1037049715575).

Almost surely, 2^{21017540900040} is an apocalyptic number.

21017540900040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21017540900040 is an abundant number, since it is smaller than the sum of its proper divisors (45353640896760).

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

21017540900040 is a wasteful number, since it uses less digits than its factorization.

21017540900040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9218219726 (or 9218219722 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 33.

The spelling of 21017540900040 in words is "twenty-one trillion, seventeen billion, five hundred forty million, nine hundred thousand, forty".