55777999 has 4 divisors (see below), whose sum is σ = 57138480. Its totient is φ = 54417520.

The previous prime is 55777993. The next prime is 55778027. The reversal of 55777999 is 99977755.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99977755 = 5 ⋅19995551.

It is a cyclic number.

It is not a de Polignac number, because 55777999 - 2¹⁵ = 55745231 is a prime.

It is a super-2 number, since 2×55777999² = 6222370344888002, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55777993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 680179 + ... + 680260.

It is an arithmetic number, because the mean of its divisors is an integer number (14284620).

Almost surely, 2^55777999 is an apocalyptic number.

55777999 is a deficient number, since it is larger than the sum of its proper divisors (1360481).

55777999 is a wasteful number, since it uses less digits than its factorization.

55777999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360480.

The product of its digits is 6251175, while the sum is 58.

The square root of 55777999 is about 7468.4669779012. The cubic root of 55777999 is about 382.0800043500.

The spelling of 55777999 in words is "fifty-five million, seven hundred seventy-seven thousand, nine hundred ninety-nine".