55420121 has 2 divisors, whose sum is σ = 55420122. Its totient is φ = 55420120.

The previous prime is 55420111. The next prime is 55420129. The reversal of 55420121 is 12102455.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55294096 + 126025 = 7436^2 + 355^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55420121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 55420093 and 55420102.

It is not a weakly prime, because it can be changed into another prime (55420129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27710060 + 27710061.

It is an arithmetic number, because the mean of its divisors is an integer number (27710061).

Almost surely, 2^55420121 is an apocalyptic number.

It is an amenable number.

55420121 is a deficient number, since it is larger than the sum of its proper divisors (1).

55420121 is an equidigital number, since it uses as much as digits as its factorization.

55420121 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 55420121 is about 7444.4691550170. The cubic root of 55420121 is about 381.2610941500.

Adding to 55420121 its reverse (12102455), we get a palindrome (67522576).

The spelling of 55420121 in words is "fifty-five million, four hundred twenty thousand, one hundred twenty-one".