128661250 has 20 divisors (see below), whose sum is σ = 241164990. Its totient is φ = 51464000.

The previous prime is 128661233. The next prime is 128661277. The reversal of 128661250 is 52166821.

It can be written as a sum of positive squares in 5 ways, for example, as 22344529 + 106316721 = 4727^2 + 10311^2 .

It is a zygodrome in base 3.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 50215 + ... + 52714.

Almost surely, 2^128661250 is an apocalyptic number.

128661250 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

128661250 is a deficient number, since it is larger than the sum of its proper divisors (112503740).

128661250 is an equidigital number, since it uses as much as digits as its factorization.

128661250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102951 (or 102936 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 128661250 is about 11342.8942514686. The cubic root of 128661250 is about 504.8347660577.

It can be divided in two parts, 128 and 661250, that multiplied together give a square (84640000 = 9200²).

The spelling of 128661250 in words is "one hundred twenty-eight million, six hundred sixty-one thousand, two hundred fifty".