65689337981 has 16 divisors (see below), whose sum is σ = 68328054144. Its totient is φ = 63097205184.

The previous prime is 65689337971. The next prime is 65689337999. The reversal of 65689337981 is 18973398656.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65689337981 is a prime.

It is a super-2 number, since 2×65689337981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65689337941) 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, 4577840 + ... + 4592166.

It is an arithmetic number, because the mean of its divisors is an integer number (4270503384).

Almost surely, 2^65689337981 is an apocalyptic number.

It is an amenable number.

65689337981 is a deficient number, since it is larger than the sum of its proper divisors (2638716163).

65689337981 is a wasteful number, since it uses less digits than its factorization.

65689337981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15940.

The product of its digits is 58786560, while the sum is 65.

The spelling of 65689337981 in words is "sixty-five billion, six hundred eighty-nine million, three hundred thirty-seven thousand, nine hundred eighty-one".