65431531 has 16 divisors (see below), whose sum is σ = 74390400. Its totient is φ = 57025600.

The previous prime is 65431529. The next prime is 65431547. The reversal of 65431531 is 13513456.

It is a cyclic number.

It is not a de Polignac number, because 65431531 - 2¹ = 65431529 is a prime.

It is a super-2 number, since 2×65431531² = 8562570498007922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 65431531.

It is not an unprimeable number, because it can be changed into a prime (65431031) 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, 25380 + ... + 27838.

It is an arithmetic number, because the mean of its divisors is an integer number (4649400).

Almost surely, 2^65431531 is an apocalyptic number.

65431531 is the 3618-th centered decagonal number.

65431531 is a deficient number, since it is larger than the sum of its proper divisors (8958869).

65431531 is a wasteful number, since it uses less digits than its factorization.

65431531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2570.

The product of its digits is 5400, while the sum is 28.

The square root of 65431531 is about 8088.9758931524. The cubic root of 65431531 is about 402.9603923909.

Adding to 65431531 its reverse (13513456), we get a palindrome (78944987).

The spelling of 65431531 in words is "sixty-five million, four hundred thirty-one thousand, five hundred thirty-one".