55151021 has 2 divisors, whose sum is σ = 55151022. Its totient is φ = 55151020.

The previous prime is 55151003. The next prime is 55151023. The reversal of 55151021 is 12015155.

It is a happy number.

55151021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37393225 + 17757796 = 6115^2 + 4214^2 .

It is a cyclic number.

It is not a de Polignac number, because 55151021 - 2⁶ = 55150957 is a prime.

Together with 55151023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 55150984 and 55151002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55151023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27575510 + 27575511.

It is an arithmetic number, because the mean of its divisors is an integer number (27575511).

Almost surely, 2^55151021 is an apocalyptic number.

It is an amenable number.

55151021 is a deficient number, since it is larger than the sum of its proper divisors (1).

55151021 is an equidigital number, since it uses as much as digits as its factorization.

55151021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 250, while the sum is 20.

The square root of 55151021 is about 7426.3733410057. The cubic root of 55151021 is about 380.6430041464.

Adding to 55151021 its reverse (12015155), we get a palindrome (67166176).

The spelling of 55151021 in words is "fifty-five million, one hundred fifty-one thousand, twenty-one".