139440 has 80 divisors (see below), whose sum is σ = 499968. Its totient is φ = 31488.

The previous prime is 139439. The next prime is 139457. The reversal of 139440 is 44931.

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 (21).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 139440.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1639 + ... + 1721.

2¹³⁹⁴⁴⁰ is an apocalyptic number.

139440 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 139440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249984).

139440 is an abundant number, since it is smaller than the sum of its proper divisors (360528).

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

139440 is a wasteful number, since it uses less digits than its factorization.

139440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 139440 is about 373.4166573681. The cubic root of 139440 is about 51.8556152471.

It can be divided in two parts, 13 and 9440, that added together give a triangular number (9453 = T₁₃₇).

The spelling of 139440 in words is "one hundred thirty-nine thousand, four hundred forty".