9961420591 has 2 divisors, whose sum is σ = 9961420592. Its totient is φ = 9961420590.

The previous prime is 9961420577. The next prime is 9961420603. The reversal of 9961420591 is 1950241699.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9961420591 - 2⁵ = 9961420559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9961420531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4980710295 + 4980710296.

It is an arithmetic number, because the mean of its divisors is an integer number (4980710296).

Almost surely, 2^9961420591 is an apocalyptic number.

9961420591 is a deficient number, since it is larger than the sum of its proper divisors (1).

9961420591 is an equidigital number, since it uses as much as digits as its factorization.

9961420591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 174960, while the sum is 46.

The square root of 9961420591 is about 99806.9165489046. The cubic root of 9961420591 is about 2151.6605589205.

The spelling of 9961420591 in words is "nine billion, nine hundred sixty-one million, four hundred twenty thousand, five hundred ninety-one".