5721781 has 8 divisors (see below), whose sum is σ = 6191640. Its totient is φ = 5256192.

The previous prime is 5721767. The next prime is 5721797. The reversal of 5721781 is 1871275.

It is a happy number.

5721781 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 4900 + 5716881 = 70^2 + 2391^2 .

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 5721781 - 2⁹ = 5721269 is a prime.

It is a super-2 number, since 2×5721781² = 65477555623922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5721281) 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, 2085 + ... + 3973.

It is an arithmetic number, because the mean of its divisors is an integer number (773955).

Almost surely, 2^5721781 is an apocalyptic number.

It is an amenable number.

5721781 is a deficient number, since it is larger than the sum of its proper divisors (469859).

5721781 is a wasteful number, since it uses less digits than its factorization.

5721781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2135.

The product of its digits is 3920, while the sum is 31.

The square root of 5721781 is about 2392.0244563967. The cubic root of 5721781 is about 178.8588402621.

The spelling of 5721781 in words is "five million, seven hundred twenty-one thousand, seven hundred eighty-one".