139666520 has 64 divisors (see below), whose sum is σ = 364115520. Its totient is φ = 47222784.

The previous prime is 139666487. The next prime is 139666589. The reversal of 139666520 is 25666931.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17024 + ... + 23856.

It is an arithmetic number, because the mean of its divisors is an integer number (5689305).

Almost surely, 2^139666520 is an apocalyptic number.

139666520 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 139666520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182057760).

139666520 is an abundant number, since it is smaller than the sum of its proper divisors (224449000).

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

139666520 is a wasteful number, since it uses less digits than its factorization.

139666520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6924 (or 6920 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 139666520 is about 11818.0590622995. The cubic root of 139666520 is about 518.8367983660.

The spelling of 139666520 in words is "one hundred thirty-nine million, six hundred sixty-six thousand, five hundred twenty".