7257720 has 64 divisors (see below), whose sum is σ = 22487040. Its totient is φ = 1872000.

The previous prime is 7257709. The next prime is 7257721. The reversal of 7257720 is 277527.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7257721) 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, 2745 + ... + 4695.

It is an arithmetic number, because the mean of its divisors is an integer number (351360).

Almost surely, 2^7257720 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 7257720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11243520).

7257720 is an abundant number, since it is smaller than the sum of its proper divisors (15229320).

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

7257720 is a wasteful number, since it uses less digits than its factorization.

7257720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1996 (or 1992 counting only the distinct ones).

The product of its (nonzero) digits is 6860, while the sum is 30.

The square root of 7257720 is about 2694.0155901553. The cubic root of 7257720 is about 193.6125045995.

The spelling of 7257720 in words is "seven million, two hundred fifty-seven thousand, seven hundred twenty".