139405856 has 24 divisors (see below), whose sum is σ = 277179084. Its totient is φ = 69011200.

The previous prime is 139405841. The next prime is 139405859. The reversal of 139405856 is 658504931.

It can be written as a sum of positive squares in 2 ways, for example, as 136515856 + 2890000 = 11684^2 + 1700^2 .

It is not an unprimeable number, because it can be changed into a prime (139405859) 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, 18335 + ... + 24798.

Almost surely, 2^139405856 is an apocalyptic number.

139405856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

139405856 is a deficient number, since it is larger than the sum of its proper divisors (137773228).

139405856 is a wasteful number, since it uses less digits than its factorization.

139405856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43244 (or 43236 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 41.

The square root of 139405856 is about 11807.0257050622. The cubic root of 139405856 is about 518.5138235685.

The spelling of 139405856 in words is "one hundred thirty-nine million, four hundred five thousand, eight hundred fifty-six".