21162284640 has 576 divisors, whose sum is σ = 86718340800. Its totient is φ = 4805885952.

The previous prime is 21162284597. The next prime is 21162284677. The reversal of 21162284640 is 4648226112.

21162284640 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 2 + 2 + 8 + 4 + 640 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21162284595 and 21162284604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 54401566 + ... + 54401954.

It is an arithmetic number, because the mean of its divisors is an integer number (150552675).

Almost surely, 2^21162284640 is an apocalyptic number.

21162284640 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 21162284640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43359170400).

21162284640 is an abundant number, since it is smaller than the sum of its proper divisors (65556056160).

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

21162284640 is a wasteful number, since it uses less digits than its factorization.

21162284640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684 (or 663 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The spelling of 21162284640 in words is "twenty-one billion, one hundred sixty-two million, two hundred eighty-four thousand, six hundred forty".