128440455 has 32 divisors (see below), whose sum is σ = 241436160. Its totient is φ = 57482880.

The previous prime is 128440453. The next prime is 128440469. The reversal of 128440455 is 554044821.

It is a happy number.

It is not a de Polignac number, because 128440455 - 2¹ = 128440453 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128440451) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27795 + ... + 32084.

It is an arithmetic number, because the mean of its divisors is an integer number (7544880).

Almost surely, 2^128440455 is an apocalyptic number.

128440455 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

128440455 is a deficient number, since it is larger than the sum of its proper divisors (112995705).

128440455 is a wasteful number, since it uses less digits than its factorization.

128440455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59911.

The product of its (nonzero) digits is 25600, while the sum is 33.

The square root of 128440455 is about 11333.1573270647. The cubic root of 128440455 is about 504.5458191407.

The spelling of 128440455 in words is "one hundred twenty-eight million, four hundred forty thousand, four hundred fifty-five".