55777921 has 8 divisors (see below), whose sum is σ = 58512384. Its totient is φ = 53069280.

The previous prime is 55777903. The next prime is 55777937. The reversal of 55777921 is 12977755.

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

It is not a de Polignac number, because 55777921 - 2⁷ = 55777793 is a prime.

It is a super-2 number, since 2×55777921² = 6222352942164482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55777021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1956 + ... + 10741.

It is an arithmetic number, because the mean of its divisors is an integer number (7314048).

Almost surely, 2^55777921 is an apocalyptic number.

It is an amenable number.

55777921 is a deficient number, since it is larger than the sum of its proper divisors (2734463).

55777921 is a wasteful number, since it uses less digits than its factorization.

55777921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12911.

The product of its digits is 154350, while the sum is 43.

The square root of 55777921 is about 7468.4617559441. The cubic root of 55777921 is about 382.0798262495.

The spelling of 55777921 in words is "fifty-five million, seven hundred seventy-seven thousand, nine hundred twenty-one".