56723281 has 4 divisors (see below), whose sum is σ = 56932864. Its totient is φ = 56513700.

The previous prime is 56723269. The next prime is 56723291. The reversal of 56723281 is 18232765.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18232765 = 5 ⋅3646553.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56723281 is a prime.

It is a super-2 number, since 2×56723281² = 6435061214809922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56723291) 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, 104385 + ... + 104926.

It is an arithmetic number, because the mean of its divisors is an integer number (14233216).

Almost surely, 2^56723281 is an apocalyptic number.

It is an amenable number.

56723281 is a deficient number, since it is larger than the sum of its proper divisors (209583).

56723281 is a wasteful number, since it uses less digits than its factorization.

56723281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209582.

The product of its digits is 20160, while the sum is 34.

The square root of 56723281 is about 7531.4859755562. The cubic root of 56723281 is about 384.2263228367.

The spelling of 56723281 in words is "fifty-six million, seven hundred twenty-three thousand, two hundred eighty-one".