667073621 has 4 divisors (see below), whose sum is σ = 667309644. Its totient is φ = 666837600.

The previous prime is 667073609. The next prime is 667073677. The reversal of 667073621 is 126370766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 268632100 + 398441521 = 16390^2 + 19961^2 .

It is a cyclic number.

It is not a de Polignac number, because 667073621 - 2¹⁰ = 667072597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667073681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113720 + ... + 119441.

It is an arithmetic number, because the mean of its divisors is an integer number (166827411).

Almost surely, 2^667073621 is an apocalyptic number.

It is an amenable number.

667073621 is a deficient number, since it is larger than the sum of its proper divisors (236023).

667073621 is a wasteful number, since it uses less digits than its factorization.

667073621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236022.

The product of its (nonzero) digits is 63504, while the sum is 38.

The square root of 667073621 is about 25827.7684092141. The cubic root of 667073621 is about 873.7581822576.

The spelling of 667073621 in words is "six hundred sixty-seven million, seventy-three thousand, six hundred twenty-one".