999990557 has 16 divisors (see below), whose sum is σ = 1057976640. Its totient is φ = 943821312.

The previous prime is 999990517. The next prime is 999990569. The reversal of 999990557 is 755099999.

It is a cyclic number.

It is not a de Polignac number, because 999990557 - 2⁸ = 999990301 is a prime.

It is a super-2 number, since 2×999990557² = 1999962228178340498, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 999990557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999990517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 231338 + ... + 235620.

It is an arithmetic number, because the mean of its divisors is an integer number (66123540).

Almost surely, 2^999990557 is an apocalyptic number.

999990557 is a gapful number since it is divisible by the number (97) formed by its first and last digit.

It is an amenable number.

999990557 is a deficient number, since it is larger than the sum of its proper divisors (57986083).

999990557 is a wasteful number, since it uses less digits than its factorization.

999990557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4492.

The product of its (nonzero) digits is 10333575, while the sum is 62.

The square root of 999990557 is about 31622.6272943916. The cubic root of 999990557 is about 999.9968523234.

The spelling of 999990557 in words is "nine hundred ninety-nine million, nine hundred ninety thousand, five hundred fifty-seven".