55143989 has 2 divisors, whose sum is σ = 55143990. Its totient is φ = 55143988.

The previous prime is 55143973. The next prime is 55144013. The reversal of 55143989 is 98934155.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48539089 + 6604900 = 6967^2 + 2570^2 .

It is a cyclic number.

It is not a de Polignac number, because 55143989 - 2⁴ = 55143973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55143929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27571994 + 27571995.

It is an arithmetic number, because the mean of its divisors is an integer number (27571995).

Almost surely, 2^55143989 is an apocalyptic number.

It is an amenable number.

55143989 is a deficient number, since it is larger than the sum of its proper divisors (1).

55143989 is an equidigital number, since it uses as much as digits as its factorization.

55143989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 194400, while the sum is 44.

The square root of 55143989 is about 7425.8998781292. The cubic root of 55143989 is about 380.6268255678.

The spelling of 55143989 in words is "fifty-five million, one hundred forty-three thousand, nine hundred eighty-nine".