623540989 has 2 divisors, whose sum is σ = 623540990. Its totient is φ = 623540988.

The previous prime is 623540947. The next prime is 623541013. The reversal of 623540989 is 989045326.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 382515364 + 241025625 = 19558^2 + 15525^2 .

It is a cyclic number.

It is not a de Polignac number, because 623540989 - 2¹⁹ = 623016701 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (623540089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 311770494 + 311770495.

It is an arithmetic number, because the mean of its divisors is an integer number (311770495).

Almost surely, 2^623540989 is an apocalyptic number.

It is an amenable number.

623540989 is a deficient number, since it is larger than the sum of its proper divisors (1).

623540989 is an equidigital number, since it uses as much as digits as its factorization.

623540989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 466560, while the sum is 46.

The square root of 623540989 is about 24970.8027303889. The cubic root of 623540989 is about 854.3221553126.

The spelling of 623540989 in words is "six hundred twenty-three million, five hundred forty thousand, nine hundred eighty-nine".