1550421 has 10 divisors (see below), whose sum is σ = 2316182. Its totient is φ = 1033560.

The previous prime is 1550413. The next prime is 1550431. The reversal of 1550421 is 1240551.

It can be written as a sum of positive squares in only one way, i.e., 1347921 + 202500 = 1161^2 + 450^2 .

It is not a de Polignac number, because 1550421 - 2³ = 1550413 is a prime.

It is a Duffinian number.

It is a Curzon number.

1550421 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1550394 and 1550403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1550401) 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 9 ways as a sum of consecutive naturals, for example, 9490 + ... + 9651.

2^1550421 is an apocalyptic number.

It is an amenable number.

1550421 is a deficient number, since it is larger than the sum of its proper divisors (765761).

1550421 is an equidigital number, since it uses as much as digits as its factorization.

1550421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19153 (or 19144 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 1550421 is about 1245.1590259882. The cubic root of 1550421 is about 115.7399296487.

Adding to 1550421 its reverse (1240551), we get a palindrome (2790972).

The spelling of 1550421 in words is "one million, five hundred fifty thousand, four hundred twenty-one".