7221981 has 16 divisors (see below), whose sum is σ = 10422720. Its totient is φ = 4421760.

The previous prime is 7221967. The next prime is 7221983. The reversal of 7221981 is 1891227.

7221981 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 7221981 - 2⁶ = 7221917 is a prime.

It is a super-2 number, since 2×7221981² = 104314019128722, which 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 (7221983) 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, 10630 + ... + 11288.

It is an arithmetic number, because the mean of its divisors is an integer number (651420).

Almost surely, 2^7221981 is an apocalyptic number.

It is an amenable number.

7221981 is a deficient number, since it is larger than the sum of its proper divisors (3200739).

7221981 is a wasteful number, since it uses less digits than its factorization.

7221981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956.

The product of its digits is 2016, while the sum is 30.

The square root of 7221981 is about 2687.3743691566. The cubic root of 7221981 is about 193.2941811985.

The spelling of 7221981 in words is "seven million, two hundred twenty-one thousand, nine hundred eighty-one".