1309128 has 16 divisors (see below), whose sum is σ = 3272880. Its totient is φ = 436368.

The previous prime is 1309127. The next prime is 1309129. The reversal of 1309128 is 8219031.

It is an interprime number because it is at equal distance from previous prime (1309127) and next prime (1309129).

It is a super-2 number, since 2×1309128² = 3427632240768, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 54547 = 1309128 / (1 + 3 + 0 + 9 + 1 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 1309098 and 1309107.

It is not an unprimeable number, because it can be changed into a prime (1309123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27250 + ... + 27297.

It is an arithmetic number, because the mean of its divisors is an integer number (204555).

2^1309128 is an apocalyptic number.

It is an amenable number.

1309128 is an abundant number, since it is smaller than the sum of its proper divisors (1963752).

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

1309128 is a wasteful number, since it uses less digits than its factorization.

1309128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54556 (or 54552 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 1309128 is about 1144.1713158439. The cubic root of 1309128 is about 109.3941346659.

Subtracting 1309128 from its reverse (8219031), we obtain a triangular number (6909903 = T₃₇₁₇).

The spelling of 1309128 in words is "one million, three hundred nine thousand, one hundred twenty-eight".