55109381 has 2 divisors, whose sum is σ = 55109382. Its totient is φ = 55109380.

The previous prime is 55109377. The next prime is 55109389. The reversal of 55109381 is 18390155.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48302500 + 6806881 = 6950^2 + 2609^2 .

It is a cyclic number.

It is not a de Polignac number, because 55109381 - 2² = 55109377 is a prime.

It is a super-2 number, since 2×55109381² = 6074087748406322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55109389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27554690 + 27554691.

It is an arithmetic number, because the mean of its divisors is an integer number (27554691).

Almost surely, 2^55109381 is an apocalyptic number.

It is an amenable number.

55109381 is a deficient number, since it is larger than the sum of its proper divisors (1).

55109381 is an equidigital number, since it uses as much as digits as its factorization.

55109381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 55109381 is about 7423.5692897689. The cubic root of 55109381 is about 380.5471826180.

The spelling of 55109381 in words is "fifty-five million, one hundred nine thousand, three hundred eighty-one".