921730680 has 192 divisors, whose sum is σ = 3313870560. Its totient is φ = 220713984.

The previous prime is 921730673. The next prime is 921730721. The reversal of 921730680 is 86037129.

921730680 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 170499 + ... + 175821.

Almost surely, 2^921730680 is an apocalyptic number.

921730680 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 921730680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1656935280).

921730680 is an abundant number, since it is smaller than the sum of its proper divisors (2392139880).

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

921730680 is a wasteful number, since it uses less digits than its factorization.

921730680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5390 (or 5383 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 921730680 is about 30360.0177865561. The cubic root of 921730680 is about 973.1983137704.

The spelling of 921730680 in words is "nine hundred twenty-one million, seven hundred thirty thousand, six hundred eighty".