990134557 has 2 divisors, whose sum is σ = 990134558. Its totient is φ = 990134556.

The previous prime is 990134507. The next prime is 990134569. The reversal of 990134557 is 755431099.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 947962521 + 42172036 = 30789^2 + 6494^2 .

It is an emirp because it is prime and its reverse (755431099) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 990134557 - 2¹¹ = 990132509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990134507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495067278 + 495067279.

It is an arithmetic number, because the mean of its divisors is an integer number (495067279).

Almost surely, 2^990134557 is an apocalyptic number.

It is an amenable number.

990134557 is a deficient number, since it is larger than the sum of its proper divisors (1).

990134557 is an equidigital number, since it uses as much as digits as its factorization.

990134557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 170100, while the sum is 43.

The square root of 990134557 is about 31466.4036235474. The cubic root of 990134557 is about 996.7006452301.

The spelling of 990134557 in words is "nine hundred ninety million, one hundred thirty-four thousand, five hundred fifty-seven".