1661250 has 40 divisors (see below), whose sum is σ = 4161168. Its totient is φ = 442000.

The previous prime is 1661249. The next prime is 1661251. The reversal of 1661250 is 521661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1661249) and next prime (1661251).

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1661251) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3529 + ... + 3971.

2^1661250 is an apocalyptic number.

1661250 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2080584).

1661250 is an abundant number, since it is smaller than the sum of its proper divisors (2499918).

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

1661250 is an equidigital number, since it uses as much as digits as its factorization.

1661250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468 (or 453 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 1661250 is about 1288.8948754650. The cubic root of 1661250 is about 118.4345273816.

The spelling of 1661250 in words is "one million, six hundred sixty-one thousand, two hundred fifty".