20417249664 has 256 divisors, whose sum is σ = 69151104000. Its totient is φ = 5809508352.

The previous prime is 20417249621. The next prime is 20417249669. The reversal of 20417249664 is 46694271402.

It is a super-2 number, since 2×20417249664² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20417249669) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6360892 + ... + 6364100.

It is an arithmetic number, because the mean of its divisors is an integer number (270121500).

Almost surely, 2^20417249664 is an apocalyptic number.

20417249664 is a gapful number since it is divisible by the number (24) 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 20417249664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34575552000).

20417249664 is an abundant number, since it is smaller than the sum of its proper divisors (48733854336).

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

20417249664 is a wasteful number, since it uses less digits than its factorization.

20417249664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3502 (or 3484 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The spelling of 20417249664 in words is "twenty billion, four hundred seventeen million, two hundred forty-nine thousand, six hundred sixty-four".