55987213 has 4 divisors (see below), whose sum is σ = 56003868. Its totient is φ = 55970560.

The previous prime is 55987207. The next prime is 55987237. The reversal of 55987213 is 31278955.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31278955 = 5 ⋅6255791.

It can be written as a sum of positive squares in 2 ways, for example, as 53904964 + 2082249 = 7342^2 + 1443^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55987213 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55987013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1318 + ... + 10663.

It is an arithmetic number, because the mean of its divisors is an integer number (14000967).

Almost surely, 2^55987213 is an apocalyptic number.

It is an amenable number.

55987213 is a deficient number, since it is larger than the sum of its proper divisors (16655).

55987213 is a wasteful number, since it uses less digits than its factorization.

55987213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16654.

The product of its digits is 75600, while the sum is 40.

The square root of 55987213 is about 7482.4603573958. The cubic root of 55987213 is about 382.5571145151.

The spelling of 55987213 in words is "fifty-five million, nine hundred eighty-seven thousand, two hundred thirteen".