990990128 has 10 divisors (see below), whose sum is σ = 1920043404. Its totient is φ = 495495056.

The previous prime is 990990127. The next prime is 990990149. The reversal of 990990128 is 821099099.

It is a super-2 number, since 2×990990128² = 1964122867586912768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (990990127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30968426 + ... + 30968457.

Almost surely, 2^990990128 is an apocalyptic number.

It is an amenable number.

990990128 is a deficient number, since it is larger than the sum of its proper divisors (929053276).

990990128 is a wasteful number, since it uses less digits than its factorization.

990990128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61936891 (or 61936885 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 47.

The square root of 990990128 is about 31479.9956797964. The cubic root of 990990128 is about 996.9876441573.

The spelling of 990990128 in words is "nine hundred ninety million, nine hundred ninety thousand, one hundred twenty-eight".