990868691 has 8 divisors (see below), whose sum is σ = 1005864384. Its totient is φ = 975945960.

The previous prime is 990868679. The next prime is 990868721. The reversal of 990868691 is 196868099.

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 990868691 - 2¹⁴ = 990852307 is a prime.

It is not an unprimeable number, because it can be changed into a prime (990868661) 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, 9440 + ... + 45506.

It is an arithmetic number, because the mean of its divisors is an integer number (125733048).

Almost surely, 2^990868691 is an apocalyptic number.

990868691 is a deficient number, since it is larger than the sum of its proper divisors (14995693).

990868691 is a wasteful number, since it uses less digits than its factorization.

990868691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36481.

The product of its (nonzero) digits is 1679616, while the sum is 56.

The square root of 990868691 is about 31478.0668243779. The cubic root of 990868691 is about 996.9469185130.

The spelling of 990868691 in words is "nine hundred ninety million, eight hundred sixty-eight thousand, six hundred ninety-one".