551878991 has 2 divisors, whose sum is σ = 551878992. Its totient is φ = 551878990.

The previous prime is 551878949. The next prime is 551878993. The reversal of 551878991 is 199878155.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 551878991 - 2⁶ = 551878927 is a prime.

Together with 551878993, 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 (551878993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275939495 + 275939496.

It is an arithmetic number, because the mean of its divisors is an integer number (275939496).

Almost surely, 2^551878991 is an apocalyptic number.

551878991 is a deficient number, since it is larger than the sum of its proper divisors (1).

551878991 is an equidigital number, since it uses as much as digits as its factorization.

551878991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 907200, while the sum is 53.

The square root of 551878991 is about 23492.1048652521. The cubic root of 551878991 is about 820.2532387588.

The spelling of 551878991 in words is "five hundred fifty-one million, eight hundred seventy-eight thousand, nine hundred ninety-one".