990438799 has 4 divisors (see below), whose sum is σ = 1131930064. Its totient is φ = 848947536.

The previous prime is 990438791. The next prime is 990438847. The reversal of 990438799 is 997834099.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 990438799 - 2³ = 990438791 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990438791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70745622 + ... + 70745635.

It is an arithmetic number, because the mean of its divisors is an integer number (282982516).

Almost surely, 2^990438799 is an apocalyptic number.

990438799 is a deficient number, since it is larger than the sum of its proper divisors (141491265).

990438799 is a wasteful number, since it uses less digits than its factorization.

990438799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141491264.

The product of its (nonzero) digits is 4408992, while the sum is 58.

The square root of 990438799 is about 31471.2376464606. The cubic root of 990438799 is about 996.8027213038.

The spelling of 990438799 in words is "nine hundred ninety million, four hundred thirty-eight thousand, seven hundred ninety-nine".