55776309 has 16 divisors (see below), whose sum is σ = 77137920. Its totient is φ = 35806400.

The previous prime is 55776283. The next prime is 55776377. The reversal of 55776309 is 90367755.

55776309 = 952² + 953² + ... + 1009².

It is a cyclic number.

It is not a de Polignac number, because 55776309 - 2⁸ = 55776053 is a prime.

It is a super-2 number, since 2×55776309² = 6221993291326962, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55776709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47884 + ... + 49034.

It is an arithmetic number, because the mean of its divisors is an integer number (4821120).

Almost surely, 2^55776309 is an apocalyptic number.

It is an amenable number.

55776309 is a deficient number, since it is larger than the sum of its proper divisors (21361611).

55776309 is a wasteful number, since it uses less digits than its factorization.

55776309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740.

The product of its (nonzero) digits is 198450, while the sum is 42.

The square root of 55776309 is about 7468.3538346814. The cubic root of 55776309 is about 382.0761454705.

The spelling of 55776309 in words is "fifty-five million, seven hundred seventy-six thousand, three hundred nine".