128699631 has 16 divisors (see below), whose sum is σ = 196817920. Its totient is φ = 83031480.

The previous prime is 128699609. The next prime is 128699671. The reversal of 128699631 is 136996821.

It is a happy number.

128699631 is a `hidden beast` number, since 1 + 2 + 8 + 6 + 9 + 9 + 631 = 666.

It is not a de Polignac number, because 128699631 - 2⁶ = 128699567 is a prime.

It is a super-2 number, since 2×128699631² = 33127190039072322, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128699671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76045 + ... + 77718.

It is an arithmetic number, because the mean of its divisors is an integer number (12301120).

Almost surely, 2^128699631 is an apocalyptic number.

128699631 is a deficient number, since it is larger than the sum of its proper divisors (68118289).

128699631 is a wasteful number, since it uses less digits than its factorization.

128699631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153803 (or 153797 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 128699631 is about 11344.5859774608. The cubic root of 128699631 is about 504.8849602350.

It can be divided in two parts, 12869 and 9631, that added together give a square (22500 = 150²).

The spelling of 128699631 in words is "one hundred twenty-eight million, six hundred ninety-nine thousand, six hundred thirty-one".