21135442218840 has 96 divisors (see below), whose sum is σ = 68863210818480. Its totient is φ = 5621921116416.

The previous prime is 21135442218833. The next prime is 21135442218893. The reversal of 21135442218840 is 4881224453112.

21135442218840 is a `hidden beast` number, since 2 + 1 + 1 + 3 + 5 + 4 + 422 + 188 + 40 = 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 pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73798594 + ... + 74084433.

Almost surely, 2^{21135442218840} is an apocalyptic number.

21135442218840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21135442218840 is an abundant number, since it is smaller than the sum of its proper divisors (47727768599640).

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

21135442218840 is a wasteful number, since it uses less digits than its factorization.

21135442218840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147883441 (or 147883434 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The spelling of 21135442218840 in words is "twenty-one trillion, one hundred thirty-five billion, four hundred forty-two million, two hundred eighteen thousand, eight hundred forty".