1621872 has 60 divisors (see below), whose sum is σ = 5190640. Its totient is φ = 463104.

The previous prime is 1621871. The next prime is 1621877. The reversal of 1621872 is 2781261.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621871) 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, 204 + ... + 1812.

2^1621872 is an apocalyptic number.

1621872 is a gapful number since it is divisible by the number (12) 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 1621872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2595320).

1621872 is an abundant number, since it is smaller than the sum of its proper divisors (3568768).

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

1621872 is a wasteful number, since it uses less digits than its factorization.

1621872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1630 (or 1621 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 1621872 is about 1273.5273848646. The cubic root of 1621872 is about 117.4912502916.

It can be divided in two parts, 16218 and 72, that added together give a triangular number (16290 = T₁₈₀).

The spelling of 1621872 in words is "one million, six hundred twenty-one thousand, eight hundred seventy-two".