55023781 has 4 divisors (see below), whose sum is σ = 58260492. Its totient is φ = 51787072.

The previous prime is 55023767. The next prime is 55023809. The reversal of 55023781 is 18732055.

55023781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38750625 + 16273156 = 6225^2 + 4034^2 .

It is a cyclic number.

It is not a de Polignac number, because 55023781 - 2⁷ = 55023653 is a prime.

It is a super-2 number, since 2×55023781² = 6055232951071922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55026781) 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 3 ways as a sum of consecutive naturals, for example, 1618330 + ... + 1618363.

It is an arithmetic number, because the mean of its divisors is an integer number (14565123).

Almost surely, 2^55023781 is an apocalyptic number.

It is an amenable number.

55023781 is a deficient number, since it is larger than the sum of its proper divisors (3236711).

55023781 is a wasteful number, since it uses less digits than its factorization.

55023781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3236710.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 55023781 is about 7417.8016285150. The cubic root of 55023781 is about 380.3500490949.

The spelling of 55023781 in words is "fifty-five million, twenty-three thousand, seven hundred eighty-one".