11907981 has 6 divisors (see below), whose sum is σ = 17200430. Its totient is φ = 7938648.

The previous prime is 11907971. The next prime is 11907983. The reversal of 11907981 is 18970911.

11907981 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 9455625 + 2452356 = 3075^2 + 1566^2 .

It is a de Polignac number, because none of the positive numbers 2^k-11907981 is a prime.

It is a super-2 number, since 2×11907981² = 283600022992722, 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 (11907983) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 661546 + ... + 661563.

Almost surely, 2^11907981 is an apocalyptic number.

It is an amenable number.

11907981 is a deficient number, since it is larger than the sum of its proper divisors (5292449).

11907981 is a wasteful number, since it uses less digits than its factorization.

11907981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1323115 (or 1323112 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 36.

The square root of 11907981 is about 3450.7942563995. The cubic root of 11907981 is about 228.3561492939.

The spelling of 11907981 in words is "eleven million, nine hundred seven thousand, nine hundred eighty-one".