921641 has 8 divisors (see below), whose sum is σ = 1075200. Its totient is φ = 789684.

The previous prime is 921637. The next prime is 921643. The reversal of 921641 is 146129.

It is a happy number.

It is not a de Polignac number, because 921641 - 2² = 921637 is a prime.

It is not an unprimeable number, because it can be changed into a prime (921643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1001 + ... + 1686.

It is an arithmetic number, because the mean of its divisors is an integer number (134400).

2⁹²¹⁶⁴¹ is an apocalyptic number.

It is an amenable number.

921641 is a deficient number, since it is larger than the sum of its proper divisors (153559).

921641 is an equidigital number, since it uses as much as digits as its factorization.

921641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2708 (or 2694 counting only the distinct ones).

The product of its digits is 432, while the sum is 23.

The square root of 921641 is about 960.0213539292. The cubic root of 921641 is about 97.3166750228.

The spelling of 921641 in words is "nine hundred twenty-one thousand, six hundred forty-one".