21617041464 has 72 divisors (see below), whose sum is σ = 61108552440. Its totient is φ = 6890482368.

The previous prime is 21617041463. The next prime is 21617041477. The reversal of 21617041464 is 46414071612.

It is a happy number.

21617041464 is a `hidden beast` number, since 2 + 16 + 170 + 414 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21617041463) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 5981322 + ... + 5984934.

It is an arithmetic number, because the mean of its divisors is an integer number (848729895).

Almost surely, 2^21617041464 is an apocalyptic number.

21617041464 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 21617041464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30554276220).

21617041464 is an abundant number, since it is smaller than the sum of its proper divisors (39491510976).

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

21617041464 is an equidigital number, since it uses as much as digits as its factorization.

21617041464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7261 (or 3641 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The spelling of 21617041464 in words is "twenty-one billion, six hundred seventeen million, forty-one thousand, four hundred sixty-four".