55021487 has 4 divisors (see below), whose sum is σ = 55775280. Its totient is φ = 54267696.

The previous prime is 55021481. The next prime is 55021489. The reversal of 55021487 is 78412055.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78412055 = 5 ⋅15682411.

It is a cyclic number.

It is not a de Polignac number, because 55021487 - 2⁴ = 55021471 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55021481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 376787 + ... + 376932.

It is an arithmetic number, because the mean of its divisors is an integer number (13943820).

Almost surely, 2^55021487 is an apocalyptic number.

55021487 is a deficient number, since it is larger than the sum of its proper divisors (753793).

55021487 is an equidigital number, since it uses as much as digits as its factorization.

55021487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753792.

The product of its (nonzero) digits is 11200, while the sum is 32.

The square root of 55021487 is about 7417.6469988804. The cubic root of 55021487 is about 380.3447632887.

The spelling of 55021487 in words is "fifty-five million, twenty-one thousand, four hundred eighty-seven".