555487991 has 2 divisors, whose sum is σ = 555487992. Its totient is φ = 555487990.

The previous prime is 555487979. The next prime is 555488027. The reversal of 555487991 is 199784555.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-555487991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (555487901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 277743995 + 277743996.

It is an arithmetic number, because the mean of its divisors is an integer number (277743996).

Almost surely, 2^555487991 is an apocalyptic number.

555487991 is a deficient number, since it is larger than the sum of its proper divisors (1).

555487991 is an equidigital number, since it uses as much as digits as its factorization.

555487991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2268000, while the sum is 53.

The square root of 555487991 is about 23568.7927353100. The cubic root of 555487991 is about 822.0373643879.

The spelling of 555487991 in words is "five hundred fifty-five million, four hundred eighty-seven thousand, nine hundred ninety-one".