921645 has 16 divisors (see below), whose sum is σ = 1638720. Its totient is φ = 491472.

The previous prime is 921643. The next prime is 921647. The reversal of 921645 is 546129.

It is an interprime number because it is at equal distance from previous prime (921643) and next prime (921647).

It is not a de Polignac number, because 921645 - 2¹ = 921643 is a prime.

It is a super-3 number, since 3×921645³ = 2348617371241233375, which contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 921645.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3279 + ... + 3548.

It is an arithmetic number, because the mean of its divisors is an integer number (102420).

2⁹²¹⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

921645 is a deficient number, since it is larger than the sum of its proper divisors (717075).

921645 is a wasteful number, since it uses less digits than its factorization.

921645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6841 (or 6835 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 921645 is about 960.0234372139. The cubic root of 921645 is about 97.3168158102.

It can be divided in two parts, 9216 and 45, that added together give a cube (9261 = 21³).

The spelling of 921645 in words is "nine hundred twenty-one thousand, six hundred forty-five".