999865004557 has 2 divisors, whose sum is σ = 999865004558. Its totient is φ = 999865004556.

The previous prime is 999865004549. The next prime is 999865004573. The reversal of 999865004557 is 755400568999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 662651353156 + 337213651401 = 814034^2 + 580701^2 .

It is a cyclic number.

It is not a de Polignac number, because 999865004557 - 2³ = 999865004549 is a prime.

It is the 999933-rd Hogben number.

It is a junction number, because it is equal to n+sod(n) for n = 999865004492 and 999865004501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999865002557) by changing a digit.

It is a nontrivial repunit in base 999932.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499932502278 + 499932502279.

It is an arithmetic number, because the mean of its divisors is an integer number (499932502279).

Almost surely, 2^999865004557 is an apocalyptic number.

It is an amenable number.

999865004557 is a deficient number, since it is larger than the sum of its proper divisors (1).

999865004557 is an equidigital number, since it uses as much as digits as its factorization.

999865004557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 122472000, while the sum is 67.

The spelling of 999865004557 in words is "nine hundred ninety-nine billion, eight hundred sixty-five million, four thousand, five hundred fifty-seven".