20347021517440 has 128 divisors (see below), whose sum is σ = 49505652835200. Its totient is φ = 7994995396608.

The previous prime is 20347021517437. The next prime is 20347021517447. The reversal of 20347021517440 is 4471512074302.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 20347021517393 and 20347021517402.

It is not an unprimeable number, because it can be changed into a prime (20347021517447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14733042 + ... + 16054798.

It is an arithmetic number, because the mean of its divisors is an integer number (386762912775).

Almost surely, 2^{20347021517440} is an apocalyptic number.

20347021517440 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 20347021517440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24752826417600).

20347021517440 is an abundant number, since it is smaller than the sum of its proper divisors (29158631317760).

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

20347021517440 is a wasteful number, since it uses less digits than its factorization.

20347021517440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1322202 (or 1322190 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 40.

The spelling of 20347021517440 in words is "twenty trillion, three hundred forty-seven billion, twenty-one million, five hundred seventeen thousand, four hundred forty".