128511631 has 2 divisors, whose sum is σ = 128511632. Its totient is φ = 128511630.

The previous prime is 128511577. The next prime is 128511637. The reversal of 128511631 is 136115821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128511631 - 2¹⁵ = 128478863 is a prime.

It is a super-2 number, since 2×128511631² = 33030478604560322, 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 128511631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128511637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64255815 + 64255816.

It is an arithmetic number, because the mean of its divisors is an integer number (64255816).

Almost surely, 2^128511631 is an apocalyptic number.

128511631 is a deficient number, since it is larger than the sum of its proper divisors (1).

128511631 is an equidigital number, since it uses as much as digits as its factorization.

128511631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 28.

The square root of 128511631 is about 11336.2970585637. The cubic root of 128511631 is about 504.6390008976.

The spelling of 128511631 in words is "one hundred twenty-eight million, five hundred eleven thousand, six hundred thirty-one".