55399999 has 8 divisors (see below), whose sum is σ = 56978640. Its totient is φ = 53841216.

The previous prime is 55399969. The next prime is 55400003. The reversal of 55399999 is 99999355.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-55399999 is a prime.

It is a Duffinian number.

55399999 is a modest number, since divided by 9999 gives 5539 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55399969) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 787 + ... + 10555.

It is an arithmetic number, because the mean of its divisors is an integer number (7122330).

Almost surely, 2^55399999 is an apocalyptic number.

55399999 is a deficient number, since it is larger than the sum of its proper divisors (1578641).

55399999 is a wasteful number, since it uses less digits than its factorization.

55399999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9929.

The product of its digits is 4428675, while the sum is 58.

The square root of 55399999 is about 7443.1175591952. The cubic root of 55399999 is about 381.2149456617.

The spelling of 55399999 in words is "fifty-five million, three hundred ninety-nine thousand, nine hundred ninety-nine".