920643840 has 288 divisors, whose sum is σ = 3461391360. Its totient is φ = 230916096.

The previous prime is 920643833. The next prime is 920643853. The reversal of 920643840 is 48346029.

It is a happy number.

920643840 is a `hidden beast` number, since 9 + 2 + 0 + 643 + 8 + 4 + 0 = 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 a junction number, because it is equal to n+sod(n) for n = 920643795 and 920643804.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 586737 + ... + 588303.

It is an arithmetic number, because the mean of its divisors is an integer number (12018720).

Almost surely, 2^920643840 is an apocalyptic number.

920643840 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 920643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1730695680).

920643840 is an abundant number, since it is smaller than the sum of its proper divisors (2540747520).

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

920643840 is a wasteful number, since it uses less digits than its factorization.

920643840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1614 (or 1594 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 920643840 is about 30342.1133080740. The cubic root of 920643840 is about 972.8156543245.

Adding to 920643840 its reverse (48346029), we get a palindrome (968989869).

The spelling of 920643840 in words is "nine hundred twenty million, six hundred forty-three thousand, eight hundred forty".