21171366432 has 288 divisors, whose sum is σ = 65799796608. Its totient is φ = 6431612928.

The previous prime is 21171366427. The next prime is 21171366457. The reversal of 21171366432 is 23466317112.

21171366432 is a `hidden beast` number, since 2 + 1 + 1 + 7 + 1 + 3 + 6 + 643 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21537013 + ... + 21537995.

It is an arithmetic number, because the mean of its divisors is an integer number (228471516).

Almost surely, 2^21171366432 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21171366432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32899898304).

21171366432 is an abundant number, since it is smaller than the sum of its proper divisors (44628430176).

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

21171366432 is a wasteful number, since it uses less digits than its factorization.

21171366432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1152 (or 1141 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The spelling of 21171366432 in words is "twenty-one billion, one hundred seventy-one million, three hundred sixty-six thousand, four hundred thirty-two".