990879977 has 2 divisors, whose sum is σ = 990879978. Its totient is φ = 990879976.

The previous prime is 990879973. The next prime is 990879983. The reversal of 990879977 is 779978099.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 927263401 + 63616576 = 30451^2 + 7976^2 .

It is an emirp because it is prime and its reverse (779978099) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 990879977 - 2² = 990879973 is a prime.

It is not a weakly prime, because it can be changed into another prime (990879973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495439988 + 495439989.

It is an arithmetic number, because the mean of its divisors is an integer number (495439989).

Almost surely, 2^990879977 is an apocalyptic number.

It is an amenable number.

990879977 is a deficient number, since it is larger than the sum of its proper divisors (1).

990879977 is an equidigital number, since it uses as much as digits as its factorization.

990879977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18003384, while the sum is 65.

The square root of 990879977 is about 31478.2460915471. The cubic root of 990879977 is about 996.9507035756.

The spelling of 990879977 in words is "nine hundred ninety million, eight hundred seventy-nine thousand, nine hundred seventy-seven".