747840 has 112 divisors (see below), whose sum is σ = 2560320. Its totient is φ = 184320.

The previous prime is 747839. The next prime is 747841. The reversal of 747840 is 48747.

It is an interprime number because it is at equal distance from previous prime (747839) and next prime (747841).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 747798 and 747807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (747841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18220 + ... + 18260.

It is an arithmetic number, because the mean of its divisors is an integer number (22860).

2⁷⁴⁷⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 747840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1280160).

747840 is an abundant number, since it is smaller than the sum of its proper divisors (1812480).

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

747840 is a wasteful number, since it uses less digits than its factorization.

747840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 30.

The square root of 747840 is about 864.7774280125. Note that the first 3 decimals coincide. The cubic root of 747840 is about 90.7687239860.

The spelling of 747840 in words is "seven hundred forty-seven thousand, eight hundred forty".