55866381 has 4 divisors (see below), whose sum is σ = 74488512. Its totient is φ = 37244252.

The previous prime is 55866373. The next prime is 55866407. The reversal of 55866381 is 18366855.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 55866381 - 2³ = 55866373 is a prime.

It is a super-2 number, since 2×55866381² = 6242105052074322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55866341) 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, 9311061 + ... + 9311066.

It is an arithmetic number, because the mean of its divisors is an integer number (18622128).

Almost surely, 2^55866381 is an apocalyptic number.

It is an amenable number.

55866381 is a deficient number, since it is larger than the sum of its proper divisors (18622131).

55866381 is a wasteful number, since it uses less digits than its factorization.

55866381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18622130.

The product of its digits is 172800, while the sum is 42.

The square root of 55866381 is about 7474.3816466648. The cubic root of 55866381 is about 382.2817037967.

The spelling of 55866381 in words is "fifty-five million, eight hundred sixty-six thousand, three hundred eighty-one".