21055931371440 has 480 divisors, whose sum is σ = 85923614215296. Its totient is φ = 4510879580160.

The previous prime is 21055931371427. The next prime is 21055931371469. The reversal of 21055931371440 is 4417313955012.

21055931371440 is a `hidden beast` number, since 2 + 1 + 0 + 5 + 593 + 1 + 3 + 7 + 14 + 40 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 20139024 + ... + 21158736.

Almost surely, 2^{21055931371440} is an apocalyptic number.

21055931371440 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 21055931371440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42961807107648).

21055931371440 is an abundant number, since it is smaller than the sum of its proper divisors (64867682843856).

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

21055931371440 is a wasteful number, since it uses less digits than its factorization.

21055931371440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1019997 (or 1019988 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 45.

The spelling of 21055931371440 in words is "twenty-one trillion, fifty-five billion, nine hundred thirty-one million, three hundred seventy-one thousand, four hundred forty".