11921531 has 4 divisors (see below), whose sum is σ = 12549000. Its totient is φ = 11294064.

The previous prime is 11921519. The next prime is 11921537. The reversal of 11921531 is 13512911.

11921531 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 11921531 - 2¹⁸ = 11659387 is a prime.

It is a super-2 number, since 2×11921531² = 284245802767922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11921497 and 11921506.

It is not an unprimeable number, because it can be changed into a prime (11921537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313706 + ... + 313743.

It is an arithmetic number, because the mean of its divisors is an integer number (3137250).

Almost surely, 2^11921531 is an apocalyptic number.

11921531 is a deficient number, since it is larger than the sum of its proper divisors (627469).

11921531 is an equidigital number, since it uses as much as digits as its factorization.

11921531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627468.

The product of its digits is 270, while the sum is 23.

The square root of 11921531 is about 3452.7570143293. The cubic root of 11921531 is about 228.4427313638.

The spelling of 11921531 in words is "eleven million, nine hundred twenty-one thousand, five hundred thirty-one".