7217640 has 128 divisors (see below), whose sum is σ = 24796800. Its totient is φ = 1866240.

The previous prime is 7217629. The next prime is 7217657. The reversal of 7217640 is 467127.

7217640 is a `hidden beast` number, since 7 + 2 + 17 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44199 + ... + 44361.

It is an arithmetic number, because the mean of its divisors is an integer number (193725).

Almost surely, 2^7217640 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 7217640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12398400).

7217640 is an abundant number, since it is smaller than the sum of its proper divisors (17579160).

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

7217640 is a wasteful number, since it uses less digits than its factorization.

7217640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 7217640 is about 2686.5665820895. The cubic root of 7217640 is about 193.2554449101.

The spelling of 7217640 in words is "seven million, two hundred seventeen thousand, six hundred forty".