4167721 has 2 divisors, whose sum is σ = 4167722. Its totient is φ = 4167720.

The previous prime is 4167719. The next prime is 4167731. The reversal of 4167721 is 1277614.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3956121 + 211600 = 1989^2 + 460^2 .

It is a cyclic number.

It is not a de Polignac number, because 4167721 - 2¹ = 4167719 is a prime.

Together with 4167719, it forms a pair of twin primes.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 4167721.

It is not a weakly prime, because it can be changed into another prime (4167731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2083860 + 2083861.

It is an arithmetic number, because the mean of its divisors is an integer number (2083861).

Almost surely, 2^4167721 is an apocalyptic number.

It is an amenable number.

4167721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4167721 is an equidigital number, since it uses as much as digits as its factorization.

4167721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2352, while the sum is 28.

The square root of 4167721 is about 2041.4996938525. The cubic root of 4167721 is about 160.9284689248.

The spelling of 4167721 in words is "four million, one hundred sixty-seven thousand, seven hundred twenty-one".