128783919 has 16 divisors (see below), whose sum is σ = 197182080. Its totient is φ = 73942560.

The previous prime is 128783903. The next prime is 128783927. The reversal of 128783919 is 919387821.

It is not a de Polignac number, because 128783919 - 2⁴ = 128783903 is a prime.

It is a super-2 number, since 2×128783919² = 33170595585997122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128783929) 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, 102072 + ... + 103325.

It is an arithmetic number, because the mean of its divisors is an integer number (12323880).

Almost surely, 2^128783919 is an apocalyptic number.

128783919 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

128783919 is a deficient number, since it is larger than the sum of its proper divisors (68398161).

128783919 is a wasteful number, since it uses less digits than its factorization.

128783919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205430.

The product of its digits is 217728, while the sum is 48.

The square root of 128783919 is about 11348.3002692033. The cubic root of 128783919 is about 504.9951559840.

The spelling of 128783919 in words is "one hundred twenty-eight million, seven hundred eighty-three thousand, nine hundred nineteen".