921165165217440 has 2304 divisors, whose sum is σ = 3886617449594880. Its totient is φ = 195490088386560.

The previous prime is 921165165217399. The next prime is 921165165217481. The reversal of 921165165217440 is 44712561561129.

921165165217440 is a `hidden beast` number, since 9 + 2 + 1 + 1 + 6 + 5 + 1 + 6 + 521 + 74 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (921165165217399) and next prime (921165165217481).

It is a super-2 number, since 2×921165165217440² (a number of 31 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 324696919702 + ... + 324696922538.

It is an arithmetic number, because the mean of its divisors is an integer number (1686899934720).

Almost surely, 2^{921165165217440} is an apocalyptic number.

921165165217440 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 921165165217440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1943308724797440).

921165165217440 is an abundant number, since it is smaller than the sum of its proper divisors (2965452284377440).

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

921165165217440 is a wasteful number, since it uses less digits than its factorization.

921165165217440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3467 (or 3456 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 921165165217440 in words is "nine hundred twenty-one trillion, one hundred sixty-five billion, one hundred sixty-five million, two hundred seventeen thousand, four hundred forty".