66091965 has 16 divisors (see below), whose sum is σ = 105920448. Its totient is φ = 35191296.

The previous prime is 66091931. The next prime is 66091967. The reversal of 66091965 is 56919066.

It is not a de Polignac number, because 66091965 - 2¹¹ = 66089917 is a prime.

It is a super-2 number, since 2×66091965² = 8736295675122450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66091967) 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, 6822 + ... + 13368.

It is an arithmetic number, because the mean of its divisors is an integer number (6620028).

Almost surely, 2^66091965 is an apocalyptic number.

It is an amenable number.

66091965 is a deficient number, since it is larger than the sum of its proper divisors (39828483).

66091965 is a wasteful number, since it uses less digits than its factorization.

66091965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7228.

The product of its (nonzero) digits is 87480, while the sum is 42.

The square root of 66091965 is about 8129.6964887996. The cubic root of 66091965 is about 404.3116182999.

The spelling of 66091965 in words is "sixty-six million, ninety-one thousand, nine hundred sixty-five".