20756521417 has 8 divisors (see below), whose sum is σ = 21538271232. Its totient is φ = 19981783200.

The previous prime is 20756521397. The next prime is 20756521421. The reversal of 20756521417 is 71412565702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20756521417 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20756521417.

It is not an unprimeable number, because it can be changed into a prime (20756521447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1746868 + ... + 1758709.

It is an arithmetic number, because the mean of its divisors is an integer number (2692283904).

Almost surely, 2^20756521417 is an apocalyptic number.

It is an amenable number.

20756521417 is a deficient number, since it is larger than the sum of its proper divisors (781749815).

20756521417 is a wasteful number, since it uses less digits than its factorization.

20756521417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3505799.

The product of its (nonzero) digits is 117600, while the sum is 40.

The spelling of 20756521417 in words is "twenty billion, seven hundred fifty-six million, five hundred twenty-one thousand, four hundred seventeen".