21745170731340 has 144 divisors (see below), whose sum is σ = 75683591343360. Its totient is φ = 4950522576000.

The previous prime is 21745170731321. The next prime is 21745170731437. The reversal of 21745170731340 is 4313707154712.

21745170731340 is a `hidden beast` number, since 2 + 1 + 74 + 5 + 170 + 73 + 1 + 340 = 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 47 ways as a sum of consecutive naturals, for example, 34062370 + ... + 34694889.

It is an arithmetic number, because the mean of its divisors is an integer number (525580495440).

Almost surely, 2^{21745170731340} is an apocalyptic number.

21745170731340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21745170731340 is an abundant number, since it is smaller than the sum of its proper divisors (53938420612020).

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

21745170731340 is a wasteful number, since it uses less digits than its factorization.

21745170731340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68757532 (or 68757527 counting only the distinct ones).

The product of its (nonzero) digits is 493920, while the sum is 45.

The spelling of 21745170731340 in words is "twenty-one trillion, seven hundred forty-five billion, one hundred seventy million, seven hundred thirty-one thousand, three hundred forty".