128978751 has 16 divisors (see below), whose sum is σ = 187803648. Its totient is φ = 78086400.

The previous prime is 128978749. The next prime is 128978753. The reversal of 128978751 is 157879821.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (128978749) and next prime (128978753).

It is not a de Polignac number, because 128978751 - 2¹ = 128978749 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128978751.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128978753) 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, 47215 + ... + 49871.

It is an arithmetic number, because the mean of its divisors is an integer number (11737728).

Almost surely, 2^128978751 is an apocalyptic number.

128978751 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

128978751 is a deficient number, since it is larger than the sum of its proper divisors (58824897).

128978751 is a wasteful number, since it uses less digits than its factorization.

128978751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4142.

The product of its digits is 282240, while the sum is 48.

The square root of 128978751 is about 11356.8812180105. The cubic root of 128978751 is about 505.2496899411.

It can be divided in two parts, 128 and 978751, that added together give a palindrome (978879).

The spelling of 128978751 in words is "one hundred twenty-eight million, nine hundred seventy-eight thousand, seven hundred fifty-one".