55691281 has 8 divisors (see below), whose sum is σ = 57767400. Its totient is φ = 53625600.

The previous prime is 55691267. The next prime is 55691291. The reversal of 55691281 is 18219655.

It can be written as a sum of positive squares in 4 ways, for example, as 12250000 + 43441281 = 3500^2 + 6591^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 55691281 - 2⁵ = 55691249 is a prime.

It is a super-2 number, since 2×55691281² = 6203037558841922, which contains 22 as substring.

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 55691281.

It is not an unprimeable number, because it can be changed into a prime (55691291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9235 + ... + 14023.

It is an arithmetic number, because the mean of its divisors is an integer number (7220925).

Almost surely, 2^55691281 is an apocalyptic number.

It is an amenable number.

55691281 is a deficient number, since it is larger than the sum of its proper divisors (2076119).

55691281 is a wasteful number, since it uses less digits than its factorization.

55691281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5219.

The product of its digits is 21600, while the sum is 37.

The square root of 55691281 is about 7462.6591105316. The cubic root of 55691281 is about 381.8818951792.

The spelling of 55691281 in words is "fifty-five million, six hundred ninety-one thousand, two hundred eighty-one".