139979840 has 448 divisors, whose sum is σ = 491581440. Its totient is φ = 36495360.

The previous prime is 139979831. The next prime is 139979857. The reversal of 139979840 is 48979931.

It is a tau number, because it is divible by the number of its divisors (448).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6086069 + ... + 6086091.

It is an arithmetic number, because the mean of its divisors is an integer number (1097280).

Almost surely, 2^139979840 is an apocalyptic number.

139979840 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 139979840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245790720).

139979840 is an abundant number, since it is smaller than the sum of its proper divisors (351601600).

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

139979840 is a wasteful number, since it uses less digits than its factorization.

139979840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 80 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 139979840 is about 11831.3076200393. The cubic root of 139979840 is about 519.2244850170.

Subtracting from 139979840 its reverse (48979931), we obtain a palindrome (90999909).

It can be divided in two parts, 139 and 979840, that added together give a palindrome (979979).

The spelling of 139979840 in words is "one hundred thirty-nine million, nine hundred seventy-nine thousand, eight hundred forty".