65236438981 has 4 divisors (see below), whose sum is σ = 74555930272. Its totient is φ = 55916947692.

The previous prime is 65236438973. The next prime is 65236438987. The reversal of 65236438981 is 18983463256.

65236438981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 65236438981 - 2³ = 65236438973 is a prime.

It is a super-2 number, since 2×65236438981² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65236438987) 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, 4659745635 + ... + 4659745648.

It is an arithmetic number, because the mean of its divisors is an integer number (18638982568).

Almost surely, 2^65236438981 is an apocalyptic number.

It is an amenable number.

65236438981 is a deficient number, since it is larger than the sum of its proper divisors (9319491291).

65236438981 is an equidigital number, since it uses as much as digits as its factorization.

65236438981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9319491290.

The product of its digits is 7464960, while the sum is 55.

The spelling of 65236438981 in words is "sixty-five billion, two hundred thirty-six million, four hundred thirty-eight thousand, nine hundred eighty-one".