11921749 has 6 divisors (see below), whose sum is σ = 13868214. Its totient is φ = 10218600.

The previous prime is 11921729. The next prime is 11921753. The reversal of 11921749 is 94712911.

11921749 = T₃₂₇ + T₃₂₈ + ... + T₄₇₃.

11921749 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., 7800849 + 4120900 = 2793^2 + 2030^2 .

It is not a de Polignac number, because 11921749 - 2¹⁷ = 11790677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11921719) 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, 121602 + ... + 121699.

It is an arithmetic number, because the mean of its divisors is an integer number (2311369).

Almost surely, 2^11921749 is an apocalyptic number.

It is an amenable number.

11921749 is a deficient number, since it is larger than the sum of its proper divisors (1946465).

11921749 is an equidigital number, since it uses as much as digits as its factorization.

11921749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243315 (or 243308 counting only the distinct ones).

The product of its digits is 4536, while the sum is 34.

The square root of 11921749 is about 3452.7885831600. The cubic root of 11921749 is about 228.4441238084. Note that the first 3 decimals are identical.

The spelling of 11921749 in words is "eleven million, nine hundred twenty-one thousand, seven hundred forty-nine".