55640047 has 2 divisors, whose sum is σ = 55640048. Its totient is φ = 55640046.

The previous prime is 55640033. The next prime is 55640051. The reversal of 55640047 is 74004655.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 55640047 - 2⁷ = 55639919 is a prime.

It is equal to p_3318088 and since 55640047 and 3318088 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55640147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27820023 + 27820024.

It is an arithmetic number, because the mean of its divisors is an integer number (27820024).

Almost surely, 2^55640047 is an apocalyptic number.

55640047 is a deficient number, since it is larger than the sum of its proper divisors (1).

55640047 is an equidigital number, since it uses as much as digits as its factorization.

55640047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16800, while the sum is 31.

The square root of 55640047 is about 7459.2256300503. The cubic root of 55640047 is about 381.7647533242.

The spelling of 55640047 in words is "fifty-five million, six hundred forty thousand, forty-seven".