55691393 has 4 divisors (see below), whose sum is σ = 56742228. Its totient is φ = 54640560.

The previous prime is 55691369. The next prime is 55691453. The reversal of 55691393 is 39319655.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39319655 = 5 ⋅7863931.

It can be written as a sum of positive squares in 2 ways, for example, as 25573249 + 30118144 = 5057^2 + 5488^2 .

It is a cyclic number.

It is not a de Polignac number, because 55691393 - 2¹² = 55687297 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55691393.

It is not an unprimeable number, because it can be changed into a prime (55691333) 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, 525338 + ... + 525443.

It is an arithmetic number, because the mean of its divisors is an integer number (14185557).

Almost surely, 2^55691393 is an apocalyptic number.

55691393 is a gapful number since it is divisible by the number (53) formed by its first and last digit.

It is an amenable number.

55691393 is a deficient number, since it is larger than the sum of its proper divisors (1050835).

55691393 is a wasteful number, since it uses less digits than its factorization.

55691393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050834.

The product of its digits is 109350, while the sum is 41.

The square root of 55691393 is about 7462.6666145554. Note that the first 4 decimals coincide. The cubic root of 55691393 is about 381.8821511782.

The spelling of 55691393 in words is "fifty-five million, six hundred ninety-one thousand, three hundred ninety-three".