55423521 has 20 divisors (see below), whose sum is σ = 85035412. Its totient is φ = 35948448.

The previous prime is 55423507. The next prime is 55423541. The reversal of 55423521 is 12532455.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 37454400 + 17969121 = 6120^2 + 4239^2 .

It is not a de Polignac number, because 55423521 - 2¹⁸ = 55161377 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (55423541) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6250 + ... + 12243.

Almost surely, 2^55423521 is an apocalyptic number.

It is an amenable number.

55423521 is a deficient number, since it is larger than the sum of its proper divisors (29611891).

55423521 is a wasteful number, since it uses less digits than its factorization.

55423521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18542 (or 18533 counting only the distinct ones).

The product of its digits is 6000, while the sum is 27.

The square root of 55423521 is about 7444.6975089657. The cubic root of 55423521 is about 381.2688907239.

Adding to 55423521 its reverse (12532455), we get a palindrome (67955976).

The spelling of 55423521 in words is "fifty-five million, four hundred twenty-three thousand, five hundred twenty-one".