1961651844 has 120 divisors (see below), whose sum is σ = 5234866560. Its totient is φ = 640426176.

The previous prime is 1961651801. The next prime is 1961651869. The reversal of 1961651844 is 4481561691.

1961651844 is a `hidden beast` number, since 1 + 96 + 1 + 6 + 518 + 44 = 666.

1961651844 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 1961651844.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4427887 + ... + 4428329.

It is an arithmetic number, because the mean of its divisors is an integer number (43623888).

Almost surely, 2^1961651844 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1961651844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2617433280).

1961651844 is an abundant number, since it is smaller than the sum of its proper divisors (3273214716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1961651844 is a wasteful number, since it uses less digits than its factorization.

1961651844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 711 (or 700 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 1961651844 is about 44290.5389897210. The cubic root of 1961651844 is about 1251.8164192716.

The spelling of 1961651844 in words is "one billion, nine hundred sixty-one million, six hundred fifty-one thousand, eight hundred forty-four".