1981075965 has 16 divisors (see below), whose sum is σ = 3457878336. Its totient is φ = 960521600.

The previous prime is 1981075961. The next prime is 1981075973. The reversal of 1981075965 is 5695701891.

It is not a de Polignac number, because 1981075965 - 2² = 1981075961 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981075961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6003096 + ... + 6003425.

It is an arithmetic number, because the mean of its divisors is an integer number (216117396).

Almost surely, 2^1981075965 is an apocalyptic number.

1981075965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1981075965 is a deficient number, since it is larger than the sum of its proper divisors (1476802371).

1981075965 is a wasteful number, since it uses less digits than its factorization.

1981075965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12006540.

The product of its (nonzero) digits is 680400, while the sum is 51.

The square root of 1981075965 is about 44509.2795380918. The cubic root of 1981075965 is about 1255.9346518684.

The spelling of 1981075965 in words is "one billion, nine hundred eighty-one million, seventy-five thousand, nine hundred sixty-five".