55218739 has 4 divisors (see below), whose sum is σ = 56260656. Its totient is φ = 54176824.

The previous prime is 55218707. The next prime is 55218767. The reversal of 55218739 is 93781255.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 55218739 - 2⁵ = 55218707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55218439) 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, 520879 + ... + 520984.

It is an arithmetic number, because the mean of its divisors is an integer number (14065164).

Almost surely, 2^55218739 is an apocalyptic number.

55218739 is a deficient number, since it is larger than the sum of its proper divisors (1041917).

55218739 is a wasteful number, since it uses less digits than its factorization.

55218739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041916.

The product of its digits is 75600, while the sum is 40.

The square root of 55218739 is about 7430.9312337015. The cubic root of 55218739 is about 380.7987331471.

It can be divided in two parts, 552 and 18739, that added together give a palindrome (19291).

The spelling of 55218739 in words is "fifty-five million, two hundred eighteen thousand, seven hundred thirty-nine".