647920 has 80 divisors (see below), whose sum is σ = 1874880. Its totient is φ = 202752.

The previous prime is 647917. The next prime is 647951. The reversal of 647920 is 29746.

647920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7236 + ... + 7324.

It is an arithmetic number, because the mean of its divisors is an integer number (23436).

2⁶⁴⁷⁹²⁰ 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 647920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (937440).

647920 is an abundant number, since it is smaller than the sum of its proper divisors (1226960).

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

647920 is a wasteful number, since it uses less digits than its factorization.

647920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 116 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 647920 is about 804.9347799667. The cubic root of 647920 is about 86.5314129618.

The spelling of 647920 in words is "six hundred forty-seven thousand, nine hundred twenty".