623853661 has 2 divisors, whose sum is σ = 623853662. Its totient is φ = 623853660.

The previous prime is 623853623. The next prime is 623853673. The reversal of 623853661 is 166358326.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 571927225 + 51926436 = 23915^2 + 7206^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-623853661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (623853611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 311926830 + 311926831.

It is an arithmetic number, because the mean of its divisors is an integer number (311926831).

Almost surely, 2^623853661 is an apocalyptic number.

It is an amenable number.

623853661 is a deficient number, since it is larger than the sum of its proper divisors (1).

623853661 is an equidigital number, since it uses as much as digits as its factorization.

623853661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 40.

The square root of 623853661 is about 24977.0626976032. The cubic root of 623853661 is about 854.4649301982.

The spelling of 623853661 in words is "six hundred twenty-three million, eight hundred fifty-three thousand, six hundred sixty-one".