2355681 has 4 divisors (see below), whose sum is σ = 3140912. Its totient is φ = 1570452.

The previous prime is 2355671. The next prime is 2355697. The reversal of 2355681 is 1865532.

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.

It is not a de Polignac number, because 2355681 - 2⁹ = 2355169 is a prime.

It is a super-2 number, since 2×2355681² = 11098465947522, which contains 22 as substring.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

2355681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2355671) 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, 392611 + ... + 392616.

It is an arithmetic number, because the mean of its divisors is an integer number (785228).

2^2355681 is an apocalyptic number.

It is an amenable number.

2355681 is a deficient number, since it is larger than the sum of its proper divisors (785231).

2355681 is an equidigital number, since it uses as much as digits as its factorization.

2355681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 785230.

The product of its digits is 7200, while the sum is 30.

The square root of 2355681 is about 1534.8227910739. The cubic root of 2355681 is about 133.0573367271.

The spelling of 2355681 in words is "two million, three hundred fifty-five thousand, six hundred eighty-one".