1621554 has 32 divisors (see below), whose sum is σ = 3594240. Its totient is φ = 483600.

The previous prime is 1621541. The next prime is 1621559. The reversal of 1621554 is 4551261.

It is a Curzon number.

It is a nialpdrome in base 6.

It is not an unprimeable number, because it can be changed into a prime (1621559) 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 15 ways as a sum of consecutive naturals, for example, 5059 + ... + 5369.

It is an arithmetic number, because the mean of its divisors is an integer number (112320).

2^1621554 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1621554, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1797120).

1621554 is an abundant number, since it is smaller than the sum of its proper divisors (1972686).

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

1621554 is a wasteful number, since it uses less digits than its factorization.

1621554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406.

The product of its digits is 1200, while the sum is 24.

The square root of 1621554 is about 1273.4025286609. The cubic root of 1621554 is about 117.4835709639.

The spelling of 1621554 in words is "one million, six hundred twenty-one thousand, five hundred fifty-four".