55661387 has 2 divisors, whose sum is σ = 55661388. Its totient is φ = 55661386.

The previous prime is 55661381. The next prime is 55661423. The reversal of 55661387 is 78316655.

55661387 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55661387 - 2⁴ = 55661371 is a prime.

It is not a weakly prime, because it can be changed into another prime (55661381) 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 as a sum of consecutive naturals, namely, 27830693 + 27830694.

It is an arithmetic number, because the mean of its divisors is an integer number (27830694).

Almost surely, 2^55661387 is an apocalyptic number.

55661387 is a deficient number, since it is larger than the sum of its proper divisors (1).

55661387 is an equidigital number, since it uses as much as digits as its factorization.

55661387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 151200, while the sum is 41.

The square root of 55661387 is about 7460.6559363102. The cubic root of 55661387 is about 381.8135540170.

The spelling of 55661387 in words is "fifty-five million, six hundred sixty-one thousand, three hundred eighty-seven".