13820981 has 2 divisors, whose sum is σ = 13820982. Its totient is φ = 13820980.

The previous prime is 13820959. The next prime is 13821007. The reversal of 13820981 is 18902831.

13820981 is digitally balanced in base 2 and base 3, because in such bases 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., 10080625 + 3740356 = 3175^2 + 1934^2 .

It is a cyclic number.

It is not a de Polignac number, because 13820981 - 2¹⁰ = 13819957 is a prime.

It is a super-2 number, since 2×13820981² = 382039031604722, which contains 22 as substring.

It is equal to p₈₉₉₂₁₃ and since 13820981 and 899213 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13820381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6910490 + 6910491.

It is an arithmetic number, because the mean of its divisors is an integer number (6910491).

Almost surely, 2^13820981 is an apocalyptic number.

It is an amenable number.

13820981 is a deficient number, since it is larger than the sum of its proper divisors (1).

13820981 is an equidigital number, since it uses as much as digits as its factorization.

13820981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 13820981 is about 3717.6579993324. The cubic root of 13820981 is about 239.9825276632.

The spelling of 13820981 in words is "thirteen million, eight hundred twenty thousand, nine hundred eighty-one".