55981405 has 4 divisors (see below), whose sum is σ = 67177692. Its totient is φ = 44785120.

The previous prime is 55981363. The next prime is 55981421. The reversal of 55981405 is 50418955.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50418955 = 5 ⋅10083791.

It can be written as a sum of positive squares in 2 ways, for example, as 6335289 + 49646116 = 2517^2 + 7046^2 .

It is a de Polignac number, because none of the positive numbers 2^k-55981405 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5598136 + ... + 5598145.

It is an arithmetic number, because the mean of its divisors is an integer number (16794423).

Almost surely, 2^55981405 is an apocalyptic number.

It is an amenable number.

55981405 is a deficient number, since it is larger than the sum of its proper divisors (11196287).

55981405 is a wasteful number, since it uses less digits than its factorization.

55981405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11196286.

The product of its (nonzero) digits is 36000, while the sum is 37.

The square root of 55981405 is about 7482.0722396940. The cubic root of 55981405 is about 382.5438854911.

The spelling of 55981405 in words is "fifty-five million, nine hundred eighty-one thousand, four hundred five".