990737591 has 2 divisors, whose sum is σ = 990737592. Its totient is φ = 990737590.

The previous prime is 990737563. The next prime is 990737593. The reversal of 990737591 is 195737099.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 990737591 - 2¹⁰ = 990736567 is a prime.

Together with 990737593, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990737593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495368795 + 495368796.

It is an arithmetic number, because the mean of its divisors is an integer number (495368796).

Almost surely, 2^990737591 is an apocalyptic number.

990737591 is a deficient number, since it is larger than the sum of its proper divisors (1).

990737591 is an equidigital number, since it uses as much as digits as its factorization.

990737591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 535815, while the sum is 50.

The square root of 990737591 is about 31475.9843531541. The cubic root of 990737591 is about 996.9029485074.

The spelling of 990737591 in words is "nine hundred ninety million, seven hundred thirty-seven thousand, five hundred ninety-one".