10931981 has 4 divisors (see below), whose sum is σ = 11005500. Its totient is φ = 10858464.

The previous prime is 10931957. The next prime is 10931989. The reversal of 10931981 is 18913901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18913901 = 541 ⋅34961.

It can be written as a sum of positive squares in 2 ways, for example, as 401956 + 10530025 = 634^2 + 3245^2 .

It is a cyclic number.

It is not a de Polignac number, because 10931981 - 2⁶ = 10931917 is a prime.

It is a super-2 number, since 2×10931981² = 239016417168722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10931989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36536 + ... + 36833.

It is an arithmetic number, because the mean of its divisors is an integer number (2751375).

Almost surely, 2^10931981 is an apocalyptic number.

It is an amenable number.

10931981 is a deficient number, since it is larger than the sum of its proper divisors (73519).

10931981 is an equidigital number, since it uses as much as digits as its factorization.

10931981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73518.

The product of its (nonzero) digits is 1944, while the sum is 32.

The square root of 10931981 is about 3306.3546391759. The cubic root of 10931981 is about 221.9386582136.

The spelling of 10931981 in words is "ten million, nine hundred thirty-one thousand, nine hundred eighty-one".