990666771 has 4 divisors (see below), whose sum is σ = 1320889032. Its totient is φ = 660444512.

The previous prime is 990666769. The next prime is 990666791. The reversal of 990666771 is 177666099.

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 990666771 - 2¹ = 990666769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (990666701) 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, 165111126 + ... + 165111131.

It is an arithmetic number, because the mean of its divisors is an integer number (330222258).

Almost surely, 2^990666771 is an apocalyptic number.

990666771 is a deficient number, since it is larger than the sum of its proper divisors (330222261).

990666771 is a wasteful number, since it uses less digits than its factorization.

990666771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330222260.

The product of its (nonzero) digits is 857304, while the sum is 51.

The square root of 990666771 is about 31474.8593483752. The cubic root of 990666771 is about 996.8791943705.

The spelling of 990666771 in words is "nine hundred ninety million, six hundred sixty-six thousand, seven hundred seventy-one".