55139778 has 20 divisors (see below), whose sum is σ = 123554310. Its totient is φ = 18379872.

The previous prime is 55139743. The next prime is 55139779. The reversal of 55139778 is 87793155.

55139778 is a `hidden beast` number, since 551 + 3 + 97 + 7 + 8 = 666.

55139778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 33489369 + 21650409 = 5787^2 + 4653^2 .

It is not an unprimeable number, because it can be changed into a prime (55139779) 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 9 ways as a sum of consecutive naturals, for example, 170023 + ... + 170346.

Almost surely, 2^55139778 is an apocalyptic number.

55139778 is an abundant number, since it is smaller than the sum of its proper divisors (68414532).

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

55139778 is a wasteful number, since it uses less digits than its factorization.

55139778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340383 (or 340374 counting only the distinct ones).

The product of its digits is 264600, while the sum is 45.

The square root of 55139778 is about 7425.6163380557. The cubic root of 55139778 is about 380.6171366281.

The spelling of 55139778 in words is "fifty-five million, one hundred thirty-nine thousand, seven hundred seventy-eight".