667747973 has 2 divisors, whose sum is σ = 667747974. Its totient is φ = 667747972.

The previous prime is 667747963. The next prime is 667747979. The reversal of 667747973 is 379747766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 665536804 + 2211169 = 25798^2 + 1487^2 .

It is a cyclic number.

It is not a de Polignac number, because 667747973 - 2⁶ = 667747909 is a prime.

It is a super-3 number, since 3×667747973³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667747979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333873986 + 333873987.

It is an arithmetic number, because the mean of its divisors is an integer number (333873987).

Almost surely, 2^667747973 is an apocalyptic number.

It is an amenable number.

667747973 is a deficient number, since it is larger than the sum of its proper divisors (1).

667747973 is an equidigital number, since it uses as much as digits as its factorization.

667747973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9335088, while the sum is 56.

The square root of 667747973 is about 25840.8198979831. The cubic root of 667747973 is about 874.0525136581.

It can be divided in two parts, 66774 and 7973, that added together give a palindrome (74747).

The spelling of 667747973 in words is "six hundred sixty-seven million, seven hundred forty-seven thousand, nine hundred seventy-three".