55619815 has 4 divisors (see below), whose sum is σ = 66743784. Its totient is φ = 44495848.

The previous prime is 55619813. The next prime is 55619833. The reversal of 55619815 is 51891655.

55619815 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 55619815 - 2¹ = 55619813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55619813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5561977 + ... + 5561986.

It is an arithmetic number, because the mean of its divisors is an integer number (16685946).

Almost surely, 2^55619815 is an apocalyptic number.

55619815 is a deficient number, since it is larger than the sum of its proper divisors (11123969).

55619815 is a wasteful number, since it uses less digits than its factorization.

55619815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11123968.

The product of its digits is 54000, while the sum is 40.

The square root of 55619815 is about 7457.8693337977. The cubic root of 55619815 is about 381.7184749013.

It can be divided in two parts, 5561 and 9815, that added together give a square (15376 = 124²).

The spelling of 55619815 in words is "fifty-five million, six hundred nineteen thousand, eight hundred fifteen".