55533521 has 4 divisors (see below), whose sum is σ = 57448500. Its totient is φ = 53618544.

The previous prime is 55533479. The next prime is 55533529. The reversal of 55533521 is 12533555.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8761600 + 46771921 = 2960^2 + 6839^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55533521 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 1914949 = 55533521 / (5 + 5 + 5 + 3 + 3 + 5 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (55533529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 957446 + ... + 957503.

It is an arithmetic number, because the mean of its divisors is an integer number (14362125).

Almost surely, 2^55533521 is an apocalyptic number.

It is an amenable number.

55533521 is a deficient number, since it is larger than the sum of its proper divisors (1914979).

55533521 is a wasteful number, since it uses less digits than its factorization.

55533521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1914978.

The product of its digits is 11250, while the sum is 29.

The square root of 55533521 is about 7452.0816554839. The cubic root of 55533521 is about 381.5209609744.

It can be divided in two parts, 555335 and 21, that multiplied together give a triangular number (11662035 = T₄₈₂₉).

The spelling of 55533521 in words is "fifty-five million, five hundred thirty-three thousand, five hundred twenty-one".