12780981 has 6 divisors (see below), whose sum is σ = 18461430. Its totient is φ = 8520648.

The previous prime is 12780973. The next prime is 12780983. The reversal of 12780981 is 18908721.

It can be written as a sum of positive squares in only one way, i.e., 7650756 + 5130225 = 2766^2 + 2265^2 .

It is not a de Polignac number, because 12780981 - 2³ = 12780973 is a prime.

It is a super-2 number, since 2×12780981² = 326706950644722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12780983) 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 in 5 ways as a sum of consecutive naturals, for example, 710046 + ... + 710063.

It is an arithmetic number, because the mean of its divisors is an integer number (3076905).

Almost surely, 2^12780981 is an apocalyptic number.

It is an amenable number.

12780981 is a deficient number, since it is larger than the sum of its proper divisors (5680449).

12780981 is a wasteful number, since it uses less digits than its factorization.

12780981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1420115 (or 1420112 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 12780981 is about 3575.0497898631. The cubic root of 12780981 is about 233.8055035155.

The spelling of 12780981 in words is "twelve million, seven hundred eighty thousand, nine hundred eighty-one".