990872101 has 2 divisors, whose sum is σ = 990872102. Its totient is φ = 990872100.

The previous prime is 990872041. The next prime is 990872119. The reversal of 990872101 is 101278099.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 980316100 + 10556001 = 31310^2 + 3249^2 .

It is a cyclic number.

It is not a de Polignac number, because 990872101 - 2²⁷ = 856654373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990872171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495436050 + 495436051.

It is an arithmetic number, because the mean of its divisors is an integer number (495436051).

Almost surely, 2^990872101 is an apocalyptic number.

It is an amenable number.

990872101 is a deficient number, since it is larger than the sum of its proper divisors (1).

990872101 is an equidigital number, since it uses as much as digits as its factorization.

990872101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 990872101 is about 31478.1209890298. The cubic root of 990872101 is about 996.9480621509.

The spelling of 990872101 in words is "nine hundred ninety million, eight hundred seventy-two thousand, one hundred one".