55809217 has 4 divisors (see below), whose sum is σ = 55854000. Its totient is φ = 55764436.

The previous prime is 55809203. The next prime is 55809233. The reversal of 55809217 is 71290855.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55809217 is a prime.

It is a super-3 number, since 3×55809217³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55869217) 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, 20467 + ... + 23032.

It is an arithmetic number, because the mean of its divisors is an integer number (13963500).

Almost surely, 2^55809217 is an apocalyptic number.

It is an amenable number.

55809217 is a deficient number, since it is larger than the sum of its proper divisors (44783).

55809217 is a wasteful number, since it uses less digits than its factorization.

55809217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44782.

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 55809217 is about 7470.5566726985. The cubic root of 55809217 is about 382.1512722885.

The spelling of 55809217 in words is "fifty-five million, eight hundred nine thousand, two hundred seventeen".