1861020 has 108 divisors (see below), whose sum is σ = 6597864. Its totient is φ = 423360.

The previous prime is 1861019. The next prime is 1861021. The reversal of 1861020 is 201681.

It is an interprime number because it is at equal distance from previous prime (1861019) and next prime (1861021).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1860984 and 1861002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 8715 + ... + 8925.

2^1861020 is an apocalyptic number.

1861020 is a gapful number since it is divisible by the number (10) 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 1861020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3298932).

1861020 is an abundant number, since it is smaller than the sum of its proper divisors (4736844).

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

1861020 is a wasteful number, since it uses less digits than its factorization.

1861020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240 (or 228 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 1861020 is about 1364.1920685886. The cubic root of 1861020 is about 123.0033709169.

The spelling of 1861020 in words is "one million, eight hundred sixty-one thousand, twenty".