5551999 has 2 divisors, whose sum is σ = 5552000. Its totient is φ = 5551998.

The previous prime is 5551981. The next prime is 5552003. The reversal of 5551999 is 9991555.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 5551999 - 2⁵ = 5551967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5551919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2775999 + 2776000.

It is an arithmetic number, because the mean of its divisors is an integer number (2776000).

Almost surely, 2^5551999 is an apocalyptic number.

5551999 is a deficient number, since it is larger than the sum of its proper divisors (1).

5551999 is an equidigital number, since it uses as much as digits as its factorization.

5551999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 91125, while the sum is 43.

The square root of 5551999 is about 2356.2680238037. The cubic root of 5551999 is about 177.0719594202.

The spelling of 5551999 in words is "five million, five hundred fifty-one thousand, nine hundred ninety-nine".