1660428 has 72 divisors (see below), whose sum is σ = 5241600. Its totient is φ = 430560.

The previous prime is 1660423. The next prime is 1660433. The reversal of 1660428 is 8240661.

It is an interprime number because it is at equal distance from previous prime (1660423) and next prime (1660433).

It is a super-2 number, since 2×1660428² = 5514042286368, which contains 22 as substring.

It is a nialpdrome in base 6.

It is a zygodrome in base 6.

It is not an unprimeable number, because it can be changed into a prime (1660423) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2473 + ... + 3071.

It is an arithmetic number, because the mean of its divisors is an integer number (72800).

2^1660428 is an apocalyptic number.

1660428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1660428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2620800).

1660428 is an abundant number, since it is smaller than the sum of its proper divisors (3581172).

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

1660428 is a wasteful number, since it uses less digits than its factorization.

1660428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627 (or 622 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 1660428 is about 1288.5759581802. The cubic root of 1660428 is about 118.4149900366.

The spelling of 1660428 in words is "one million, six hundred sixty thousand, four hundred twenty-eight".