55647021 has 4 divisors (see below), whose sum is σ = 74196032. Its totient is φ = 37098012.

The previous prime is 55647019. The next prime is 55647023. The reversal of 55647021 is 12074655.

55647021 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, 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 (55647019) and next prime (55647023).

It is not a de Polignac number, because 55647021 - 2¹ = 55647019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55647021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55647023) 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, 9274501 + ... + 9274506.

It is an arithmetic number, because the mean of its divisors is an integer number (18549008).

Almost surely, 2^55647021 is an apocalyptic number.

It is an amenable number.

55647021 is a deficient number, since it is larger than the sum of its proper divisors (18549011).

55647021 is a wasteful number, since it uses less digits than its factorization.

55647021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18549010.

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 55647021 is about 7459.6930902015. The cubic root of 55647021 is about 381.7807029642.

The spelling of 55647021 in words is "fifty-five million, six hundred forty-seven thousand, twenty-one".