64531139 has 4 divisors (see below), whose sum is σ = 64595856. Its totient is φ = 64466424.

The previous prime is 64531109. The next prime is 64531151. The reversal of 64531139 is 93113546.

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 64531139 - 2¹⁶ = 64465603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64531109) 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, 30839 + ... + 32864.

It is an arithmetic number, because the mean of its divisors is an integer number (16148964).

Almost surely, 2^64531139 is an apocalyptic number.

64531139 is a deficient number, since it is larger than the sum of its proper divisors (64717).

64531139 is a wasteful number, since it uses less digits than its factorization.

64531139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64716.

The product of its digits is 9720, while the sum is 32.

The square root of 64531139 is about 8033.1275976422. The cubic root of 64531139 is about 401.1034925444.

The spelling of 64531139 in words is "sixty-four million, five hundred thirty-one thousand, one hundred thirty-nine".