1961531361 has 12 divisors (see below), whose sum is σ = 2834067600. Its totient is φ = 1307343960.

The previous prime is 1961531353. The next prime is 1961531393. The reversal of 1961531361 is 1631351691.

1961531361 is a `hidden beast` number, since 1 + 9 + 61 + 531 + 3 + 61 = 666.

It is not a de Polignac number, because 1961531361 - 2³ = 1961531353 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1961531161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10306 + ... + 63476.

It is an arithmetic number, because the mean of its divisors is an integer number (236172300).

Almost surely, 2^1961531361 is an apocalyptic number.

It is an amenable number.

1961531361 is a deficient number, since it is larger than the sum of its proper divisors (872536239).

1961531361 is a wasteful number, since it uses less digits than its factorization.

1961531361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57276 (or 57273 counting only the distinct ones).

The product of its digits is 14580, while the sum is 36.

The square root of 1961531361 is about 44289.1788250810. The cubic root of 1961531361 is about 1251.7907902444.

The spelling of 1961531361 in words is "one billion, nine hundred sixty-one million, five hundred thirty-one thousand, three hundred sixty-one".