128781250 has 56 divisors (see below), whose sum is σ = 260856036. Its totient is φ = 47400000.

The previous prime is 128781203. The next prime is 128781251. The reversal of 128781250 is 52187821.

It can be written as a sum of positive squares in 14 ways, for example, as 127260961 + 1520289 = 11281^2 + 1233^2 .

It is a sliding number, since 128781250 = 781250 + 128000000 and 1/781250 + 1/128000000 = 0.00000128781250.

It is a super-2 number, since 2×128781250² = 33169220703125000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (128781251) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 406092 + ... + 406408.

Almost surely, 2^128781250 is an apocalyptic number.

128781250 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

128781250 is an abundant number, since it is smaller than the sum of its proper divisors (132074786).

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

128781250 is an frugal number, since it uses more digits than its factorization.

128781250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362 (or 337 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 128781250 is about 11348.1826738910. The cubic root of 128781250 is about 504.9916673461.

It can be divided in two parts, 128 and 781250, that multiplied together give a 8-th power (100000000 = 10⁸).

The spelling of 128781250 in words is "one hundred twenty-eight million, seven hundred eighty-one thousand, two hundred fifty".