55783281 has 4 divisors (see below), whose sum is σ = 74377712. Its totient is φ = 37188852.

The previous prime is 55783279. The next prime is 55783283. The reversal of 55783281 is 18238755.

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 an interprime number because it is at equal distance from previous prime (55783279) and next prime (55783283).

It is not a de Polignac number, because 55783281 - 2¹ = 55783279 is a prime.

It is a super-2 number, since 2×55783281² = 6223548878249922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55783283) 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, 9297211 + ... + 9297216.

It is an arithmetic number, because the mean of its divisors is an integer number (18594428).

Almost surely, 2^55783281 is an apocalyptic number.

It is an amenable number.

55783281 is a deficient number, since it is larger than the sum of its proper divisors (18594431).

55783281 is a wasteful number, since it uses less digits than its factorization.

55783281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18594430.

The product of its digits is 67200, while the sum is 39.

The square root of 55783281 is about 7468.8205896246. The cubic root of 55783281 is about 382.0920645584.

It can be divided in two parts, 557 and 83281, that added together give a palindrome (83838).

The spelling of 55783281 in words is "fifty-five million, seven hundred eighty-three thousand, two hundred eighty-one".