7221540 has 48 divisors (see below), whose sum is σ = 21103488. Its totient is φ = 1841664.

The previous prime is 7221523. The next prime is 7221547. The reversal of 7221540 is 451227.

It is not an unprimeable number, because it can be changed into a prime (7221547) 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, 1237 + ... + 3996.

It is an arithmetic number, because the mean of its divisors is an integer number (439656).

Almost surely, 2^7221540 is an apocalyptic number.

It is an amenable number.

7221540 is an abundant number, since it is smaller than the sum of its proper divisors (13881948).

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

7221540 is a wasteful number, since it uses less digits than its factorization.

7221540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5268 (or 5266 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 7221540 is about 2687.2923175568. The cubic root of 7221540 is about 193.2902467070.

Adding to 7221540 its reverse (451227), we get a palindrome (7672767).

It can be divided in two parts, 72 and 21540, that added together give a palindrome (21612).

The spelling of 7221540 in words is "seven million, two hundred twenty-one thousand, five hundred forty".