55591966 has 8 divisors (see below), whose sum is σ = 87013584. Its totient is φ = 26587440.

The previous prime is 55591951. The next prime is 55591969. The reversal of 55591966 is 66919555.

It is a happy number.

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

It is a Harshad number since it is a multiple of its sum of digits (46), and also a Moran number because the ratio is a prime number: 1208521 = 55591966 / (5 + 5 + 5 + 9 + 1 + 9 + 6 + 6).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55591969) 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, 604215 + ... + 604306.

It is an arithmetic number, because the mean of its divisors is an integer number (10876698).

Almost surely, 2^55591966 is an apocalyptic number.

55591966 is a deficient number, since it is larger than the sum of its proper divisors (31421618).

55591966 is a wasteful number, since it uses less digits than its factorization.

55591966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208546.

The product of its digits is 364500, while the sum is 46.

The square root of 55591966 is about 7456.0020118023. The cubic root of 55591966 is about 381.6547550889.

It can be divided in two parts, 555919 and 66, that added together give a triangular number (555985 = T₁₀₅₄).

The spelling of 55591966 in words is "fifty-five million, five hundred ninety-one thousand, nine hundred sixty-six".