961862581 has 4 divisors (see below), whose sum is σ = 961935052. Its totient is φ = 961790112.

The previous prime is 961862563. The next prime is 961862641. The reversal of 961862581 is 185268169.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 132940900 + 828921681 = 11530^2 + 28791^2 .

It is a cyclic number.

It is not a de Polignac number, because 961862581 - 2⁵ = 961862549 is a prime.

It is a super-2 number, since 2×961862581² = 1850359249455963122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (961862521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9990 + ... + 44983.

It is an arithmetic number, because the mean of its divisors is an integer number (240483763).

Almost surely, 2^961862581 is an apocalyptic number.

It is an amenable number.

961862581 is a deficient number, since it is larger than the sum of its proper divisors (72471).

961862581 is a wasteful number, since it uses less digits than its factorization.

961862581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72470.

The product of its digits is 207360, while the sum is 46.

The square root of 961862581 is about 31013.9094762334. The cubic root of 961862581 is about 987.1224064245.

The spelling of 961862581 in words is "nine hundred sixty-one million, eight hundred sixty-two thousand, five hundred eighty-one".