1550 has 12 divisors (see below), whose sum is σ = 2976. Its totient is φ = 600.

The previous prime is 1549. The next prime is 1553. The reversal of 1550 is 551.

1550 is nontrivially palindromic in base 3 and base 9.

1550 is an esthetic number in base 7, because in such base its adjacent digits differ by 1.

It is a hoax number, since the sum of its digits (11) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

1550 is an undulating number in base 7.

It is a plaindrome in base 11.

It is a nialpdrome in base 5 and base 12.

It is a zygodrome in base 5.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35 + ... + 65.

It is an arithmetic number, because the mean of its divisors is an integer number (248).

2¹⁵⁵⁰ is an apocalyptic number.

1550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1550 is a deficient number, since it is larger than the sum of its proper divisors (1426).

1550 is a wasteful number, since it uses less digits than its factorization.

1550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 25, while the sum is 11.

The square root of 1550 is about 39.3700393701. The cubic root of 1550 is about 11.5729452726.

Subtracting from 1550 its reverse (551), we obtain a palindrome (999).

The spelling of 1550 in words is "one thousand, five hundred fifty".