55021157 has 2 divisors, whose sum is σ = 55021158. Its totient is φ = 55021156.

The previous prime is 55021151. The next prime is 55021159. The reversal of 55021157 is 75112055.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44742721 + 10278436 = 6689^2 + 3206^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55021157 is a prime.

Together with 55021159, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55021151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27510578 + 27510579.

It is an arithmetic number, because the mean of its divisors is an integer number (27510579).

Almost surely, 2^55021157 is an apocalyptic number.

It is an amenable number.

55021157 is a deficient number, since it is larger than the sum of its proper divisors (1).

55021157 is an equidigital number, since it uses as much as digits as its factorization.

55021157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1750, while the sum is 26.

The square root of 55021157 is about 7417.6247545963. The cubic root of 55021157 is about 380.3440028947.

The spelling of 55021157 in words is "fifty-five million, twenty-one thousand, one hundred fifty-seven".