1620438 has 8 divisors (see below), whose sum is σ = 3240888. Its totient is φ = 540144.

The previous prime is 1620431. The next prime is 1620439. The reversal of 1620438 is 8340261.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

1620438 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 135031 + ... + 135042.

It is an arithmetic number, because the mean of its divisors is an integer number (405111).

2^1620438 is an apocalyptic number.

1620438 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1620438 is a wasteful number, since it uses less digits than its factorization.

1620438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270078.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 1620438 is about 1272.9642571573. The cubic root of 1620438 is about 117.4566129234.

Adding to 1620438 its reverse (8340261), we get a palindrome (9960699).

The spelling of 1620438 in words is "one million, six hundred twenty thousand, four hundred thirty-eight".