55405213 has 4 divisors (see below), whose sum is σ = 55436668. Its totient is φ = 55373760.

The previous prime is 55405157. The next prime is 55405223. The reversal of 55405213 is 31250455.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31250455 = 5 ⋅6250091.

It can be written as a sum of positive squares in 2 ways, for example, as 17791524 + 37613689 = 4218^2 + 6133^2 .

It is a cyclic number.

It is not a de Polignac number, because 55405213 - 2¹³ = 55397021 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 (55405223) 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, 12918 + ... + 16663.

It is an arithmetic number, because the mean of its divisors is an integer number (13859167).

Almost surely, 2^55405213 is an apocalyptic number.

It is an amenable number.

55405213 is a deficient number, since it is larger than the sum of its proper divisors (31455).

55405213 is a wasteful number, since it uses less digits than its factorization.

55405213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31454.

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 55405213 is about 7443.4678074134. The cubic root of 55405213 is about 381.2269047015.

Adding to 55405213 its reverse (31250455), we get a palindrome (86655668).

The spelling of 55405213 in words is "fifty-five million, four hundred five thousand, two hundred thirteen".