139169209 has 9 divisors (see below), whose sum is σ = 142762021. Its totient is φ = 135665500.

The previous prime is 139169201. The next prime is 139169227. The reversal of 139169209 is 902961931.

The square root of 139169209 is 11797.

It is a perfect power (a square), and thus also a powerful number.

139169209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 139169209 - 2³ = 139169201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139169201) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 554334 + ... + 554584.

Almost surely, 2^139169209 is an apocalyptic number.

139169209 is the 11797-th square number.

139169209 is the 5899-th centered octagonal number.

It is an amenable number.

139169209 is a deficient number, since it is larger than the sum of its proper divisors (3592812).

139169209 is an frugal number, since it uses more digits than its factorization.

139169209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 596 (or 298 counting only the distinct ones).

The product of its (nonzero) digits is 26244, while the sum is 40.

The cubic root of 139169209 is about 518.2202580949.

Multiplying 139169209 by its product of nonzero digits (26244), we get a square (3652356720996 = 1911114²).

The spelling of 139169209 in words is "one hundred thirty-nine million, one hundred sixty-nine thousand, two hundred nine".