1623440 has 80 divisors (see below), whose sum is σ = 4666368. Its totient is φ = 511488.

The previous prime is 1623437. The next prime is 1623451. The reversal of 1623440 is 443261.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7169 + ... + 7391.

2^1623440 is an apocalyptic number.

1623440 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 1623440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2333184).

1623440 is an abundant number, since it is smaller than the sum of its proper divisors (3042928).

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

1623440 is a wasteful number, since it uses less digits than its factorization.

1623440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 1623440 is about 1274.1428491343. The cubic root of 1623440 is about 117.5291009858.

The spelling of 1623440 in words is "one million, six hundred twenty-three thousand, four hundred forty".