15980981 has 2 divisors, whose sum is σ = 15980982. Its totient is φ = 15980980.

The previous prime is 15980971. The next prime is 15980983. The reversal of 15980981 is 18908951.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15928081 + 52900 = 3991^2 + 230^2 .

It is an emirp because it is prime and its reverse (18908951) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15980981 is a prime.

It is a super-2 number, since 2×15980981² = 510783507444722, which contains 22 as substring.

Together with 15980983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15980983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7990490 + 7990491.

It is an arithmetic number, because the mean of its divisors is an integer number (7990491).

Almost surely, 2^15980981 is an apocalyptic number.

It is an amenable number.

15980981 is a deficient number, since it is larger than the sum of its proper divisors (1).

15980981 is an equidigital number, since it uses as much as digits as its factorization.

15980981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 41.

The square root of 15980981 is about 3997.6219180908. The cubic root of 15980981 is about 251.8843268984.

It can be divided in two parts, 15980 and 981, that added together give a palindrome (16961).

The spelling of 15980981 in words is "fifteen million, nine hundred eighty thousand, nine hundred eighty-one".