21177120843840 has 336 divisors, whose sum is σ = 73188614624256. Its totient is φ = 5185529856000.

The previous prime is 21177120843797. The next prime is 21177120843841. The reversal of 21177120843840 is 4834802177112.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21177120843840.

It is not an unprimeable number, because it can be changed into a prime (21177120843841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 30646140 + ... + 31329540.

Almost surely, 2^{21177120843840} is an apocalyptic number.

21177120843840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21177120843840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36594307312128).

21177120843840 is an abundant number, since it is smaller than the sum of its proper divisors (52011493780416).

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

21177120843840 is a wasteful number, since it uses less digits than its factorization.

21177120843840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683638 (or 683615 counting only the distinct ones).

The product of its (nonzero) digits is 602112, while the sum is 48.

The spelling of 21177120843840 in words is "twenty-one trillion, one hundred seventy-seven billion, one hundred twenty million, eight hundred forty-three thousand, eight hundred forty".