623839661 has 2 divisors, whose sum is σ = 623839662. Its totient is φ = 623839660.

The previous prime is 623839589. The next prime is 623839681. The reversal of 623839661 is 166938326.

623839661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 577681225 + 46158436 = 24035^2 + 6794^2 .

It is a cyclic number.

It is not a de Polignac number, because 623839661 - 2²² = 619645357 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 (623839681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 311919830 + 311919831.

It is an arithmetic number, because the mean of its divisors is an integer number (311919831).

Almost surely, 2^623839661 is an apocalyptic number.

It is an amenable number.

623839661 is a deficient number, since it is larger than the sum of its proper divisors (1).

623839661 is an equidigital number, since it uses as much as digits as its factorization.

623839661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 44.

The square root of 623839661 is about 24976.7824388971. The cubic root of 623839661 is about 854.4585384223.

The spelling of 623839661 in words is "six hundred twenty-three million, eight hundred thirty-nine thousand, six hundred sixty-one".