1398840 has 32 divisors (see below), whose sum is σ = 4196880. Its totient is φ = 372992.

The previous prime is 1398781. The next prime is 1398841. The reversal of 1398840 is 488931.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1398841) 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, 5709 + ... + 5948.

2^1398840 is an apocalyptic number.

1398840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1398840 is an abundant number, since it is smaller than the sum of its proper divisors (2798040).

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

1398840 is a wasteful number, since it uses less digits than its factorization.

1398840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11671 (or 11667 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 1398840 is about 1182.7256655708. The cubic root of 1398840 is about 111.8379885476.

Subtracting from 1398840 its reverse (488931), we obtain a palindrome (909909).

It can be divided in two parts, 13988 and 40, that added together give a triangular number (14028 = T₁₆₇).

The spelling of 1398840 in words is "one million, three hundred ninety-eight thousand, eight hundred forty".