1961280191 has 16 divisors (see below), whose sum is σ = 2239005888. Its totient is φ = 1701926400.

The previous prime is 1961280169. The next prime is 1961280197. The reversal of 1961280191 is 1910821691.

It is a cyclic number.

It is not a de Polignac number, because 1961280191 - 2¹⁴ = 1961263807 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 (1961280197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203246 + ... + 212676.

It is an arithmetic number, because the mean of its divisors is an integer number (139937868).

Almost surely, 2^1961280191 is an apocalyptic number.

1961280191 is a deficient number, since it is larger than the sum of its proper divisors (277725697).

1961280191 is a wasteful number, since it uses less digits than its factorization.

1961280191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10402.

The product of its (nonzero) digits is 7776, while the sum is 38.

The square root of 1961280191 is about 44286.3431658113. The cubic root of 1961280191 is about 1251.7373582304.

The spelling of 1961280191 in words is "one billion, nine hundred sixty-one million, two hundred eighty thousand, one hundred ninety-one".