655438813 has 2 divisors, whose sum is σ = 655438814. Its totient is φ = 655438812.

The previous prime is 655438807. The next prime is 655438837. The reversal of 655438813 is 318834556.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 354832569 + 300606244 = 18837^2 + 17338^2 .

It is a cyclic number.

It is not a de Polignac number, because 655438813 - 2⁵ = 655438781 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 655438813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (655438513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327719406 + 327719407.

It is an arithmetic number, because the mean of its divisors is an integer number (327719407).

Almost surely, 2^655438813 is an apocalyptic number.

It is an amenable number.

655438813 is a deficient number, since it is larger than the sum of its proper divisors (1).

655438813 is an equidigital number, since it uses as much as digits as its factorization.

655438813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 345600, while the sum is 43.

The square root of 655438813 is about 25601.5392701298. The cubic root of 655438813 is about 868.6484554778.

The spelling of 655438813 in words is "six hundred fifty-five million, four hundred thirty-eight thousand, eight hundred thirteen".