21008939018040 has 64 divisors (see below), whose sum is σ = 70029796730400. Its totient is φ = 5602383737856.

The previous prime is 21008939018033. The next prime is 21008939018059. The reversal of 21008939018040 is 4081093980012.

21008939018040 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 89 + 390 + 180 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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, 9726359577 + ... + 9726361736.

Almost surely, 2^{21008939018040} is an apocalyptic number.

21008939018040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21008939018040 is an abundant number, since it is smaller than the sum of its proper divisors (49020857712360).

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

21008939018040 is a wasteful number, since it uses less digits than its factorization.

21008939018040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19452721333 (or 19452721323 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The spelling of 21008939018040 in words is "twenty-one trillion, eight billion, nine hundred thirty-nine million, eighteen thousand, forty".