55245621 has 4 divisors (see below), whose sum is σ = 73660832. Its totient is φ = 36830412.

The previous prime is 55245613. The next prime is 55245629. The reversal of 55245621 is 12654255.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (55245613) and next prime (55245629).

It is not a de Polignac number, because 55245621 - 2³ = 55245613 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55245629) 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, 9207601 + ... + 9207606.

It is an arithmetic number, because the mean of its divisors is an integer number (18415208).

Almost surely, 2^55245621 is an apocalyptic number.

It is an amenable number.

55245621 is a deficient number, since it is larger than the sum of its proper divisors (18415211).

55245621 is a wasteful number, since it uses less digits than its factorization.

55245621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18415210.

The product of its digits is 12000, while the sum is 30.

The square root of 55245621 is about 7432.7398044059. The cubic root of 55245621 is about 380.8605175523.

Adding to 55245621 its reverse (12654255), we get a palindrome (67899876).

The spelling of 55245621 in words is "fifty-five million, two hundred forty-five thousand, six hundred twenty-one".