55820217 has 4 divisors (see below), whose sum is σ = 74426960. Its totient is φ = 37213476.

The previous prime is 55820207. The next prime is 55820227. The reversal of 55820217 is 71202855.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (55820207) and next prime (55820227).

It is not a de Polignac number, because 55820217 - 2⁴ = 55820201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55820207) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9303367 + ... + 9303372.

It is an arithmetic number, because the mean of its divisors is an integer number (18606740).

Almost surely, 2^55820217 is an apocalyptic number.

It is an amenable number.

55820217 is a deficient number, since it is larger than the sum of its proper divisors (18606743).

55820217 is a wasteful number, since it uses less digits than its factorization.

55820217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18606742.

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 55820217 is about 7471.2928600076. The cubic root of 55820217 is about 382.1763779853.

The spelling of 55820217 in words is "fifty-five million, eight hundred twenty thousand, two hundred seventeen".