961841821 has 4 divisors (see below), whose sum is σ = 961919200. Its totient is φ = 961764444.

The previous prime is 961841819. The next prime is 961841851. The reversal of 961841821 is 128148169.

961841821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 961841821 - 2¹ = 961841819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (961841851) 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, 15351 + ... + 46468.

It is an arithmetic number, because the mean of its divisors is an integer number (240479800).

Almost surely, 2^961841821 is an apocalyptic number.

It is an amenable number.

961841821 is a deficient number, since it is larger than the sum of its proper divisors (77379).

961841821 is a wasteful number, since it uses less digits than its factorization.

961841821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77378.

The product of its digits is 27648, while the sum is 40.

The square root of 961841821 is about 31013.5747858901. The cubic root of 961841821 is about 987.1153046448.

The spelling of 961841821 in words is "nine hundred sixty-one million, eight hundred forty-one thousand, eight hundred twenty-one".