1965216091 has 4 divisors (see below), whose sum is σ = 1979560872. Its totient is φ = 1950871312.

The previous prime is 1965216089. The next prime is 1965216107. The reversal of 1965216091 is 1906125691.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1965216091 - 2¹ = 1965216089 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1965216041) 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, 7172185 + ... + 7172458.

It is an arithmetic number, because the mean of its divisors is an integer number (494890218).

Almost surely, 2^1965216091 is an apocalyptic number.

1965216091 is a deficient number, since it is larger than the sum of its proper divisors (14344781).

1965216091 is a wasteful number, since it uses less digits than its factorization.

1965216091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14344780.

The product of its (nonzero) digits is 29160, while the sum is 40.

The square root of 1965216091 is about 44330.7578437364. The cubic root of 1965216091 is about 1252.5741281992.

The spelling of 1965216091 in words is "one billion, nine hundred sixty-five million, two hundred sixteen thousand, ninety-one".