55221993 has 12 divisors (see below), whose sum is σ = 82719728. Its totient is φ = 36814500.

The previous prime is 55221979. The next prime is 55221997. The reversal of 55221993 is 39912255.

It is a happy number.

55221993 is a `hidden beast` number, since 552 + 2 + 19 + 93 = 666.

It is not a de Polignac number, because 55221993 - 2¹⁰ = 55220969 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (55221997) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 113383 + ... + 113868.

Almost surely, 2^55221993 is an apocalyptic number.

It is an amenable number.

55221993 is a deficient number, since it is larger than the sum of its proper divisors (27497735).

55221993 is an equidigital number, since it uses as much as digits as its factorization.

55221993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227266 (or 227254 counting only the distinct ones).

The product of its digits is 24300, while the sum is 36.

The square root of 55221993 is about 7431.1501801538. The cubic root of 55221993 is about 380.8062130640.

The spelling of 55221993 in words is "fifty-five million, two hundred twenty-one thousand, nine hundred ninety-three".