921881 has 8 divisors (see below), whose sum is σ = 967680. Its totient is φ = 877072.

The previous prime is 921871. The next prime is 921887. The reversal of 921881 is 188129.

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

It is a cyclic number.

It is not a de Polignac number, because 921881 - 2¹⁴ = 905497 is a prime.

It is a super-2 number, since 2×921881² = 1699729156322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921887) 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, 2216 + ... + 2598.

It is an arithmetic number, because the mean of its divisors is an integer number (120960).

2⁹²¹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

921881 is a deficient number, since it is larger than the sum of its proper divisors (45799).

921881 is a wasteful number, since it uses less digits than its factorization.

921881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495.

The product of its digits is 1152, while the sum is 29.

The square root of 921881 is about 960.1463430124. The cubic root of 921881 is about 97.3251215419.

The spelling of 921881 in words is "nine hundred twenty-one thousand, eight hundred eighty-one".