7222015721 has 16 divisors (see below), whose sum is σ = 7344691200. Its totient is φ = 7100730000.

The previous prime is 7222015673. The next prime is 7222015751. The reversal of 7222015721 is 1275102227.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7222015721 is a prime.

It is a super-2 number, since 2×7222015721² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7222015751) 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, 7858100 + ... + 7859018.

It is an arithmetic number, because the mean of its divisors is an integer number (459043200).

Almost surely, 2^7222015721 is an apocalyptic number.

It is an amenable number.

7222015721 is a deficient number, since it is larger than the sum of its proper divisors (122675479).

7222015721 is a wasteful number, since it uses less digits than its factorization.

7222015721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1540.

The product of its (nonzero) digits is 3920, while the sum is 29.

The square root of 7222015721 is about 84982.4436045469. The cubic root of 7222015721 is about 1932.9449096376.

Adding to 7222015721 its reverse (1275102227), we get a palindrome (8497117948).

The spelling of 7222015721 in words is "seven billion, two hundred twenty-two million, fifteen thousand, seven hundred twenty-one".