55556778 has 8 divisors (see below), whose sum is σ = 111113568. Its totient is φ = 18518924.

The previous prime is 55556777. The next prime is 55556807. The reversal of 55556778 is 87765555.

It is a sphenic number, since it is the product of 3 distinct primes.

55556778 is an admirable number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (55556777) 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, 4629726 + ... + 4629737.

It is an arithmetic number, because the mean of its divisors is an integer number (13889196).

Almost surely, 2^55556778 is an apocalyptic number.

55556778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55556778 is a wasteful number, since it uses less digits than its factorization.

55556778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9259468.

The product of its digits is 1470000, while the sum is 48.

The square root of 55556778 is about 7453.6419286145. The cubic root of 55556778 is about 381.5742128630.

The spelling of 55556778 in words is "fifty-five million, five hundred fifty-six thousand, seven hundred seventy-eight".