3138781 has 12 divisors (see below), whose sum is σ = 3457920. Its totient is φ = 2838240.

The previous prime is 3138769. The next prime is 3138791. The reversal of 3138781 is 1878313.

It is not a de Polignac number, because 3138781 - 2¹⁵ = 3106013 is a prime.

It is a super-2 number, since 2×3138781² = 19703892331922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3138791) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42961 + ... + 43033.

It is an arithmetic number, because the mean of its divisors is an integer number (288160).

Almost surely, 2^3138781 is an apocalyptic number.

3138781 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

3138781 is a deficient number, since it is larger than the sum of its proper divisors (319139).

3138781 is an equidigital number, since it uses as much as digits as its factorization.

3138781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196 (or 123 counting only the distinct ones).

The product of its digits is 4032, while the sum is 31.

The square root of 3138781 is about 1771.6605205287. The cubic root of 3138781 is about 146.4154831734.

The spelling of 3138781 in words is "three million, one hundred thirty-eight thousand, seven hundred eighty-one".