55429921 has 2 divisors, whose sum is σ = 55429922. Its totient is φ = 55429920.

The previous prime is 55429901. The next prime is 55429939. The reversal of 55429921 is 12992455.

55429921 = 5264² + 5265².

55429921 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., 27720225 + 27709696 = 5265^2 + 5264^2 .

It is a cyclic number.

It is not a de Polignac number, because 55429921 - 2¹⁹ = 54905633 is a prime.

It is a super-2 number, since 2×55429921² = 6144952284132482, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (55429901) 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, 27714960 + 27714961.

It is an arithmetic number, because the mean of its divisors is an integer number (27714961).

Almost surely, 2^55429921 is an apocalyptic number.

55429921 is the 5265-th centered square number.

It is an amenable number.

55429921 is a deficient number, since it is larger than the sum of its proper divisors (1).

55429921 is an equidigital number, since it uses as much as digits as its factorization.

55429921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32400, while the sum is 37.

The square root of 55429921 is about 7445.1273326922. The cubic root of 55429921 is about 381.2835657628.

The spelling of 55429921 in words is "fifty-five million, four hundred twenty-nine thousand, nine hundred twenty-one".