11981954 has 4 divisors (see below), whose sum is σ = 17972934. Its totient is φ = 5990976.

The previous prime is 11981941. The next prime is 11981971. The reversal of 11981954 is 45918911.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 10738729 + 1243225 = 3277^2 + 1115^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2995487 + ... + 2995490.

Almost surely, 2^11981954 is an apocalyptic number.

11981954 is a deficient number, since it is larger than the sum of its proper divisors (5990980).

11981954 is an equidigital number, since it uses as much as digits as its factorization.

11981954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5990979.

The product of its digits is 12960, while the sum is 38.

The square root of 11981954 is about 3461.4959193967. The cubic root of 11981954 is about 228.8280269716.

The spelling of 11981954 in words is "eleven million, nine hundred eighty-one thousand, nine hundred fifty-four".