8921840 has 40 divisors (see below), whose sum is σ = 20876640. Its totient is φ = 3545856.

The previous prime is 8921837. The next prime is 8921863. The reversal of 8921840 is 481298.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 8921797 and 8921806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18077 + ... + 18563.

It is an arithmetic number, because the mean of its divisors is an integer number (521916).

Almost surely, 2^8921840 is an apocalyptic number.

8921840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8921840 is an abundant number, since it is smaller than the sum of its proper divisors (11954800).

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

8921840 is a wasteful number, since it uses less digits than its factorization.

8921840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 729 (or 723 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 8921840 is about 2986.9449275137. The cubic root of 8921840 is about 207.4044849991.

It can be divided in two parts, 8 and 921840, that multiplied together give a triangular number (7374720 = T₃₈₄₀).

The spelling of 8921840 in words is "eight million, nine hundred twenty-one thousand, eight hundred forty".