55991986 has 8 divisors (see below), whose sum is σ = 84064284. Its totient is φ = 27970560.

The previous prime is 55991981. The next prime is 55991987. The reversal of 55991986 is 68919955.

It can be written as a sum of positive squares in 2 ways, for example, as 45630025 + 10361961 = 6755^2 + 3219^2 .

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

It is not an unprimeable number, because it can be changed into a prime (55991981) 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, 9835 + ... + 14446.

Almost surely, 2^55991986 is an apocalyptic number.

55991986 is a deficient number, since it is larger than the sum of its proper divisors (28072298).

55991986 is a wasteful number, since it uses less digits than its factorization.

55991986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25436.

The product of its digits is 874800, while the sum is 52.

The square root of 55991986 is about 7482.7792964914. The cubic root of 55991986 is about 382.5679854094.

The spelling of 55991986 in words is "fifty-five million, nine hundred ninety-one thousand, nine hundred eighty-six".