65511631 has 2 divisors, whose sum is σ = 65511632. Its totient is φ = 65511630.

The previous prime is 65511599. The next prime is 65511643. The reversal of 65511631 is 13611556.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 65511631 - 2⁵ = 65511599 is a prime.

It is a super-2 number, since 2×65511631² = 8583547592560322, 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 65511631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65511671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32755815 + 32755816.

It is an arithmetic number, because the mean of its divisors is an integer number (32755816).

Almost surely, 2^65511631 is an apocalyptic number.

65511631 is a deficient number, since it is larger than the sum of its proper divisors (1).

65511631 is an equidigital number, since it uses as much as digits as its factorization.

65511631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2700, while the sum is 28.

The square root of 65511631 is about 8093.9255618025. The cubic root of 65511631 is about 403.1247574143.

The spelling of 65511631 in words is "sixty-five million, five hundred eleven thousand, six hundred thirty-one".