1029840 has 80 divisors (see below), whose sum is σ = 3654528. Its totient is φ = 235008.

The previous prime is 1029839. The next prime is 1029841. The reversal of 1029840 is 489201.

It is an interprime number because it is at equal distance from previous prime (1029839) and next prime (1029841).

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1029840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1029841) 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, 1374 + ... + 1986.

2^1029840 is an apocalyptic number.

1029840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1029840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1827264).

1029840 is an abundant number, since it is smaller than the sum of its proper divisors (2624688).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1029840 is a wasteful number, since it uses less digits than its factorization.

1029840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636 (or 630 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 1029840 is about 1014.8103271055. The cubic root of 1029840 is about 100.9849338701.

The spelling of 1029840 in words is "one million, twenty-nine thousand, eight hundred forty".