55421553 has 16 divisors (see below), whose sum is σ = 80946432. Its totient is φ = 33450000.

The previous prime is 55421551. The next prime is 55421557. The reversal of 55421553 is 35512455.

It is a happy number.

It is not a de Polignac number, because 55421553 - 2¹ = 55421551 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 55421553.

It is not an unprimeable number, because it can be changed into a prime (55421551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4938 + ... + 11628.

It is an arithmetic number, because the mean of its divisors is an integer number (5059152).

Almost surely, 2^55421553 is an apocalyptic number.

It is an amenable number.

55421553 is a deficient number, since it is larger than the sum of its proper divisors (25524879).

55421553 is a wasteful number, since it uses less digits than its factorization.

55421553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6956.

The product of its digits is 15000, while the sum is 30.

The square root of 55421553 is about 7444.5653331810. The cubic root of 55421553 is about 381.2643779223.

The spelling of 55421553 in words is "fifty-five million, four hundred twenty-one thousand, five hundred fifty-three".