2005453781 has 4 divisors (see below), whose sum is σ = 2111004000. Its totient is φ = 1899903564.

The previous prime is 2005453777. The next prime is 2005453783. The reversal of 2005453781 is 1873545002.

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.

It is a cyclic number.

It is not a de Polignac number, because 2005453781 - 2² = 2005453777 is a prime.

It is a super-2 number, since 2×2005453781² = 8043689735454391922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2005453783) 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, 52775081 + ... + 52775118.

It is an arithmetic number, because the mean of its divisors is an integer number (527751000).

Almost surely, 2^2005453781 is an apocalyptic number.

It is an amenable number.

2005453781 is a deficient number, since it is larger than the sum of its proper divisors (105550219).

2005453781 is a wasteful number, since it uses less digits than its factorization.

2005453781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105550218.

The product of its (nonzero) digits is 33600, while the sum is 35.

The square root of 2005453781 is about 44782.2931637048. The cubic root of 2005453781 is about 1261.0652327510.

Adding to 2005453781 its reverse (1873545002), we get a palindrome (3878998783).

The spelling of 2005453781 in words is "two billion, five million, four hundred fifty-three thousand, seven hundred eighty-one".