672640621 has 2 divisors, whose sum is σ = 672640622. Its totient is φ = 672640620.

The previous prime is 672640597. The next prime is 672640643. The reversal of 672640621 is 126046276.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 632774025 + 39866596 = 25155^2 + 6314^2 .

It is a cyclic number.

It is not a de Polignac number, because 672640621 - 2¹⁷ = 672509549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (672640691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 336320310 + 336320311.

It is an arithmetic number, because the mean of its divisors is an integer number (336320311).

Almost surely, 2^672640621 is an apocalyptic number.

It is an amenable number.

672640621 is a deficient number, since it is larger than the sum of its proper divisors (1).

672640621 is an equidigital number, since it uses as much as digits as its factorization.

672640621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 672640621 is about 25935.3160960109. The cubic root of 672640621 is about 876.1820740954.

Adding to 672640621 its reverse (126046276), we get a palindrome (798686897).

The spelling of 672640621 in words is "six hundred seventy-two million, six hundred forty thousand, six hundred twenty-one".