921566442240 has 864 divisors, whose sum is σ = 3621599916480. Its totient is φ = 214941302784.

The previous prime is 921566442227. The next prime is 921566442287. The reversal of 921566442240 is 42244665129.

It is a happy number.

921566442240 is a `hidden beast` number, since 9 + 2 + 1 + 566 + 4 + 42 + 2 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 197208544 + ... + 197213216.

It is an arithmetic number, because the mean of its divisors is an integer number (4191666570).

Almost surely, 2^921566442240 is an apocalyptic number.

921566442240 is a gapful number since it is divisible by the number (90) 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 921566442240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1810799958240).

921566442240 is an abundant number, since it is smaller than the sum of its proper divisors (2700033474240).

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

921566442240 is a wasteful number, since it uses less digits than its factorization.

921566442240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4789 (or 4772 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 45.

The spelling of 921566442240 in words is "nine hundred twenty-one billion, five hundred sixty-six million, four hundred forty-two thousand, two hundred forty".