64971911 has 4 divisors (see below), whose sum is σ = 65244000. Its totient is φ = 64699824.

The previous prime is 64971883. The next prime is 64971917. The reversal of 64971911 is 11917946.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64971911 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 (64971917) 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, 135686 + ... + 136163.

It is an arithmetic number, because the mean of its divisors is an integer number (16311000).

Almost surely, 2^64971911 is an apocalyptic number.

64971911 is a deficient number, since it is larger than the sum of its proper divisors (272089).

64971911 is a wasteful number, since it uses less digits than its factorization.

64971911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272088.

The product of its digits is 13608, while the sum is 38.

The square root of 64971911 is about 8060.5155542310. The cubic root of 64971911 is about 402.0146505061.

The spelling of 64971911 in words is "sixty-four million, nine hundred seventy-one thousand, nine hundred eleven".