990203857 has 2 divisors, whose sum is σ = 990203858. Its totient is φ = 990203856.

The previous prime is 990203831. The next prime is 990203897. The reversal of 990203857 is 758302099.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 848498641 + 141705216 = 29129^2 + 11904^2 .

It is a cyclic number.

It is not a de Polignac number, because 990203857 - 2¹⁵ = 990171089 is a prime.

It is a super-3 number, since 3×990203857³ (a number of 28 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (990203827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495101928 + 495101929.

It is an arithmetic number, because the mean of its divisors is an integer number (495101929).

Almost surely, 2^990203857 is an apocalyptic number.

It is an amenable number.

990203857 is a deficient number, since it is larger than the sum of its proper divisors (1).

990203857 is an equidigital number, since it uses as much as digits as its factorization.

990203857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 43.

The square root of 990203857 is about 31467.5047787396. The cubic root of 990203857 is about 996.7238978755.

The spelling of 990203857 in words is "nine hundred ninety million, two hundred three thousand, eight hundred fifty-seven".