4081781 has 4 divisors (see below), whose sum is σ = 4452864. Its totient is φ = 3710700.

The previous prime is 4081771. The next prime is 4081793. The reversal of 4081781 is 1871804.

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 a de Polignac number, because none of the positive numbers 2^k-4081781 is a prime.

It is a super-2 number, since 2×4081781² = 33321872263922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4081711) 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, 185525 + ... + 185546.

It is an arithmetic number, because the mean of its divisors is an integer number (1113216).

Almost surely, 2^4081781 is an apocalyptic number.

It is an amenable number.

4081781 is a deficient number, since it is larger than the sum of its proper divisors (371083).

4081781 is a wasteful number, since it uses less digits than its factorization.

4081781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371082.

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 4081781 is about 2020.3418027651. The cubic root of 4081781 is about 159.8146421191.

The spelling of 4081781 in words is "four million, eighty-one thousand, seven hundred eighty-one".