13912781 has 2 divisors, whose sum is σ = 13912782. Its totient is φ = 13912780.

The previous prime is 13912771. The next prime is 13912793. The reversal of 13912781 is 18721931.

13912781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13801225 + 111556 = 3715^2 + 334^2 .

It is a cyclic number.

It is not a de Polignac number, because 13912781 - 2¹⁴ = 13896397 is a prime.

It is a super-2 number, since 2×13912781² = 387130950307922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13912771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6956390 + 6956391.

It is an arithmetic number, because the mean of its divisors is an integer number (6956391).

Almost surely, 2^13912781 is an apocalyptic number.

It is an amenable number.

13912781 is a deficient number, since it is larger than the sum of its proper divisors (1).

13912781 is an equidigital number, since it uses as much as digits as its factorization.

13912781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 32.

The square root of 13912781 is about 3729.9840482233. The cubic root of 13912781 is about 240.5126829727.

It can be divided in two parts, 1391 and 2781, that multiplied together give a triangular number (3868371 = T₂₇₈₁).

The spelling of 13912781 in words is "thirteen million, nine hundred twelve thousand, seven hundred eighty-one".