7221015261 has 6 divisors (see below), whose sum is σ = 10430355390. Its totient is φ = 4814010168.

The previous prime is 7221015257. The next prime is 7221015271. The reversal of 7221015261 is 1625101227.

It can be written as a sum of positive squares in only one way, i.e., 7054992036 + 166023225 = 83994^2 + 12885^2 .

It is not a de Polignac number, because 7221015261 - 2² = 7221015257 is a prime.

It is a super-2 number, since 2×7221015261² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7221015211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 401167506 + ... + 401167523.

It is an arithmetic number, because the mean of its divisors is an integer number (1738392565).

Almost surely, 2^7221015261 is an apocalyptic number.

It is an amenable number.

7221015261 is a deficient number, since it is larger than the sum of its proper divisors (3209340129).

7221015261 is a wasteful number, since it uses less digits than its factorization.

7221015261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802335035 (or 802335032 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 7221015261 is about 84976.5571260686. The cubic root of 7221015261 is about 1932.8556490838.

Adding to 7221015261 its reverse (1625101227), we get a palindrome (8846116488).

The spelling of 7221015261 in words is "seven billion, two hundred twenty-one million, fifteen thousand, two hundred sixty-one".