1687428 has 36 divisors (see below), whose sum is σ = 4491760. Its totient is φ = 532656.

The previous prime is 1687421. The next prime is 1687451. The reversal of 1687428 is 8247861.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1687392 and 1687401.

It is not an unprimeable number, because it can be changed into a prime (1687421) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 550 + ... + 1917.

2^1687428 is an apocalyptic number.

1687428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1687428 is an abundant number, since it is smaller than the sum of its proper divisors (2804332).

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

1687428 is a wasteful number, since it uses less digits than its factorization.

1687428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2496 (or 2491 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 1687428 is about 1299.0103925681. The cubic root of 1687428 is about 119.0533856457.

The spelling of 1687428 in words is "one million, six hundred eighty-seven thousand, four hundred twenty-eight".