13801981 has 2 divisors, whose sum is σ = 13801982. Its totient is φ = 13801980.

The previous prime is 13801969. The next prime is 13801993. The reversal of 13801981 is 18910831.

It is a balanced prime because it is at equal distance from previous prime (13801969) and next prime (13801993).

It can be written as a sum of positive squares in only one way, i.e., 9821956 + 3980025 = 3134^2 + 1995^2 .

It is a cyclic number.

It is not a de Polignac number, because 13801981 - 2¹³ = 13793789 is a prime.

It is a super-2 number, since 2×13801981² = 380989359048722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13801951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6900990 + 6900991.

It is an arithmetic number, because the mean of its divisors is an integer number (6900991).

Almost surely, 2^13801981 is an apocalyptic number.

It is an amenable number.

13801981 is a deficient number, since it is larger than the sum of its proper divisors (1).

13801981 is an equidigital number, since it uses as much as digits as its factorization.

13801981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 31.

The square root of 13801981 is about 3715.1017482702. The cubic root of 13801981 is about 239.8725075171.

The spelling of 13801981 in words is "thirteen million, eight hundred one thousand, nine hundred eighty-one".