139186640 has 20 divisors (see below), whose sum is σ = 323609124. Its totient is φ = 55674624.

The previous prime is 139186591. The next prime is 139186643. The reversal of 139186640 is 46681931.

It can be written as a sum of positive squares in 2 ways, for example, as 68492176 + 70694464 = 8276^2 + 8408^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 139186594 and 139186603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139186643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 869837 + ... + 869996.

Almost surely, 2^139186640 is an apocalyptic number.

139186640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

139186640 is an abundant number, since it is smaller than the sum of its proper divisors (184422484).

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

139186640 is a wasteful number, since it uses less digits than its factorization.

139186640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739846 (or 1739840 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 139186640 is about 11797.7387663908. The cubic root of 139186640 is about 518.2418929576.

The spelling of 139186640 in words is "one hundred thirty-nine million, one hundred eighty-six thousand, six hundred forty".