1023639 has 8 divisors (see below), whose sum is σ = 1381632. Its totient is φ = 674040.

The previous prime is 1023601. The next prime is 1023643. The reversal of 1023639 is 9363201.

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

It is a de Polignac number, because none of the positive numbers 2^k-1023639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1023839) 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, 1807 + ... + 2304.

It is an arithmetic number, because the mean of its divisors is an integer number (172704).

2^1023639 is an apocalyptic number.

1023639 is a deficient number, since it is larger than the sum of its proper divisors (357993).

1023639 is an equidigital number, since it uses as much as digits as its factorization.

1023639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4197.

The product of its (nonzero) digits is 972, while the sum is 24.

The square root of 1023639 is about 1011.7504633060. The cubic root of 1023639 is about 100.7818380291.

It can be divided in two parts, 102 and 3639, that added together give a triangular number (3741 = T₈₆).

The spelling of 1023639 in words is "one million, twenty-three thousand, six hundred thirty-nine".