65131631 has 2 divisors, whose sum is σ = 65131632. Its totient is φ = 65131630.

The previous prime is 65131621. The next prime is 65131643. The reversal of 65131631 is 13613156.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 65131631 - 2¹⁴ = 65115247 is a prime.

It is a super-2 number, since 2×65131631² = 8484258713440322, 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 65131631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65131621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32565815 + 32565816.

It is an arithmetic number, because the mean of its divisors is an integer number (32565816).

Almost surely, 2^65131631 is an apocalyptic number.

65131631 is a deficient number, since it is larger than the sum of its proper divisors (1).

65131631 is an equidigital number, since it uses as much as digits as its factorization.

65131631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620, while the sum is 26.

The square root of 65131631 is about 8070.4170276387. The cubic root of 65131631 is about 402.3438042139.

Adding to 65131631 its reverse (13613156), we get a palindrome (78744787).

The spelling of 65131631 in words is "sixty-five million, one hundred thirty-one thousand, six hundred thirty-one".