67575721 has 2 divisors, whose sum is σ = 67575722. Its totient is φ = 67575720.

The previous prime is 67575701. The next prime is 67575737. The reversal of 67575721 is 12757576.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49632025 + 17943696 = 7045^2 + 4236^2 .

It is a cyclic number.

It is not a de Polignac number, because 67575721 - 2⁷ = 67575593 is a prime.

It is not a weakly prime, because it can be changed into another prime (67575701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33787860 + 33787861.

It is an arithmetic number, because the mean of its divisors is an integer number (33787861).

Almost surely, 2^67575721 is an apocalyptic number.

It is an amenable number.

67575721 is a deficient number, since it is larger than the sum of its proper divisors (1).

67575721 is an equidigital number, since it uses as much as digits as its factorization.

67575721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 102900, while the sum is 40.

The square root of 67575721 is about 8220.4453042399. The cubic root of 67575721 is about 407.3148362722.

The spelling of 67575721 in words is "sixty-seven million, five hundred seventy-five thousand, seven hundred twenty-one".