961257591 has 32 divisors (see below), whose sum is σ = 1628974080. Its totient is φ = 548801568.

The previous prime is 961257589. The next prime is 961257617. The reversal of 961257591 is 195752169.

961257591 is a `hidden beast` number, since 9 + 6 + 1 + 2 + 57 + 591 = 666.

It is not a de Polignac number, because 961257591 - 2¹ = 961257589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (961257541) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 393225 + ... + 395661.

It is an arithmetic number, because the mean of its divisors is an integer number (50905440).

Almost surely, 2^961257591 is an apocalyptic number.

961257591 is a deficient number, since it is larger than the sum of its proper divisors (667716489).

961257591 is a wasteful number, since it uses less digits than its factorization.

961257591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4540 (or 4534 counting only the distinct ones).

The product of its digits is 170100, while the sum is 45.

The square root of 961257591 is about 31004.1544151748. The cubic root of 961257591 is about 986.9154037305.

The spelling of 961257591 in words is "nine hundred sixty-one million, two hundred fifty-seven thousand, five hundred ninety-one".