55366781 has 2 divisors, whose sum is σ = 55366782. Its totient is φ = 55366780.

The previous prime is 55366733. The next prime is 55366783. The reversal of 55366781 is 18766355.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38019556 + 17347225 = 6166^2 + 4165^2 .

It is a cyclic number.

It is not a de Polignac number, because 55366781 - 2²² = 51172477 is a prime.

It is a super-2 number, since 2×55366781² = 6130960876603922, which contains 22 as substring.

Together with 55366783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55366783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27683390 + 27683391.

It is an arithmetic number, because the mean of its divisors is an integer number (27683391).

Almost surely, 2^55366781 is an apocalyptic number.

It is an amenable number.

55366781 is a deficient number, since it is larger than the sum of its proper divisors (1).

55366781 is an equidigital number, since it uses as much as digits as its factorization.

55366781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 151200, while the sum is 41.

The square root of 55366781 is about 7440.8857671651. The cubic root of 55366781 is about 381.1387378994.

The spelling of 55366781 in words is "fifty-five million, three hundred sixty-six thousand, seven hundred eighty-one".