11961921 has 8 divisors (see below), whose sum is σ = 16001440. Its totient is φ = 7948512.

The previous prime is 11961899. The next prime is 11961967. The reversal of 11961921 is 12916911.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 11961921 - 2¹⁵ = 11929153 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11961991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5431 + ... + 7308.

It is an arithmetic number, because the mean of its divisors is an integer number (2000180).

Almost surely, 2^11961921 is an apocalyptic number.

It is an amenable number.

11961921 is a deficient number, since it is larger than the sum of its proper divisors (4039519).

11961921 is a wasteful number, since it uses less digits than its factorization.

11961921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13055.

The product of its digits is 972, while the sum is 30.

The square root of 11961921 is about 3458.6010177527. The cubic root of 11961921 is about 228.7004276108.

The spelling of 11961921 in words is "eleven million, nine hundred sixty-one thousand, nine hundred twenty-one".