990971999 has 8 divisors (see below), whose sum is σ = 1071321840. Its totient is φ = 913441536.

The previous prime is 990971981. The next prime is 990972011. The reversal of 990971999 is 999179099.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 990971999 - 2¹⁶ = 990906463 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990971929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 704114 + ... + 705519.

It is an arithmetic number, because the mean of its divisors is an integer number (133915230).

Almost surely, 2^990971999 is an apocalyptic number.

990971999 is a deficient number, since it is larger than the sum of its proper divisors (80349841).

990971999 is a wasteful number, since it uses less digits than its factorization.

990971999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1409689.

The product of its (nonzero) digits is 3720087, while the sum is 62.

The square root of 990971999 is about 31479.7077337132. The cubic root of 990971999 is about 996.9815645477.

The spelling of 990971999 in words is "nine hundred ninety million, nine hundred seventy-one thousand, nine hundred ninety-nine".