55124021 has 2 divisors, whose sum is σ = 55124022. Its totient is φ = 55124020.

The previous prime is 55123993. The next prime is 55124029. The reversal of 55124021 is 12042155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46771921 + 8352100 = 6839^2 + 2890^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55124021 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 55123984 and 55124002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55124029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27562010 + 27562011.

It is an arithmetic number, because the mean of its divisors is an integer number (27562011).

Almost surely, 2^55124021 is an apocalyptic number.

It is an amenable number.

55124021 is a deficient number, since it is larger than the sum of its proper divisors (1).

55124021 is an equidigital number, since it uses as much as digits as its factorization.

55124021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 55124021 is about 7424.5552728766. Note that the first 3 decimals coincide. The cubic root of 55124021 is about 380.5808775316.

Adding to 55124021 its reverse (12042155), we get a palindrome (67166176).

The spelling of 55124021 in words is "fifty-five million, one hundred twenty-four thousand, twenty-one".