128979900 has 216 divisors, whose sum is σ = 471219840. Its totient is φ = 28897920.

The previous prime is 128979889. The next prime is 128979911. The reversal of 128979900 is 9979821.

It is an interprime number because it is at equal distance from previous prime (128979889) and next prime (128979911).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 371527 + ... + 371873.

Almost surely, 2^128979900 is an apocalyptic number.

128979900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128979900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235609920).

128979900 is an abundant number, since it is smaller than the sum of its proper divisors (342239940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128979900 is a wasteful number, since it uses less digits than its factorization.

128979900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 423 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 128979900 is about 11356.9318039689. The cubic root of 128979900 is about 505.2511902662.

The spelling of 128979900 in words is "one hundred twenty-eight million, nine hundred seventy-nine thousand, nine hundred".