1023645 has 16 divisors (see below), whose sum is σ = 1872000. Its totient is φ = 467904.

The previous prime is 1023643. The next prime is 1023653. The reversal of 1023645 is 5463201.

It is a happy number.

It is not a de Polignac number, because 1023645 - 2¹ = 1023643 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1023643) 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, 4770 + ... + 4979.

It is an arithmetic number, because the mean of its divisors is an integer number (117000).

2^1023645 is an apocalyptic number.

1023645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1023645 is a deficient number, since it is larger than the sum of its proper divisors (848355).

1023645 is an equidigital number, since it uses as much as digits as its factorization.

1023645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9764.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 1023645 is about 1011.7534284597. The cubic root of 1023645 is about 100.7820349377.

Adding to 1023645 its reverse (5463201), we get a palindrome (6486846).

The spelling of 1023645 in words is "one million, twenty-three thousand, six hundred forty-five".