13653781 has 2 divisors, whose sum is σ = 13653782. Its totient is φ = 13653780.

The previous prime is 13653763. The next prime is 13653791. The reversal of 13653781 is 18735631.

13653781 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13256881 + 396900 = 3641^2 + 630^2 .

It is a cyclic number.

It is not a de Polignac number, because 13653781 - 2¹¹ = 13651733 is a prime.

It is a super-2 number, since 2×13653781² = 372851471191922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13653791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6826890 + 6826891.

It is an arithmetic number, because the mean of its divisors is an integer number (6826891).

Almost surely, 2^13653781 is an apocalyptic number.

13653781 is the 1653-rd centered decagonal number.

It is an amenable number.

13653781 is a deficient number, since it is larger than the sum of its proper divisors (1).

13653781 is an equidigital number, since it uses as much as digits as its factorization.

13653781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 34.

The square root of 13653781 is about 3695.1022989898. The cubic root of 13653781 is about 239.0108653289.

The spelling of 13653781 in words is "thirteen million, six hundred fifty-three thousand, seven hundred eighty-one".