10387981 has 2 divisors, whose sum is σ = 10387982. Its totient is φ = 10387980.

The previous prime is 10387963. The next prime is 10387997. The reversal of 10387981 is 18978301.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6812100 + 3575881 = 2610^2 + 1891^2 .

It is an emirp because it is prime and its reverse (18978301) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 10387981 - 2⁹ = 10387469 is a prime.

It is a super-2 number, since 2×10387981² = 215820298512722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 10387981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10387961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5193990 + 5193991.

It is an arithmetic number, because the mean of its divisors is an integer number (5193991).

Almost surely, 2^10387981 is an apocalyptic number.

It is an amenable number.

10387981 is a deficient number, since it is larger than the sum of its proper divisors (1).

10387981 is an equidigital number, since it uses as much as digits as its factorization.

10387981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 10387981 is about 3223.0390937747. The cubic root of 10387981 is about 218.1944579746.

The spelling of 10387981 in words is "ten million, three hundred eighty-seven thousand, nine hundred eighty-one".