139499609 has 4 divisors (see below), whose sum is σ = 140335104. Its totient is φ = 138664116.

The previous prime is 139499573. The next prime is 139499627. The reversal of 139499609 is 906994931.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 139499609 - 2²⁴ = 122722393 is a prime.

It is a super-2 number, since 2×139499609² = 38920281822305762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139499629) 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, 417497 + ... + 417830.

It is an arithmetic number, because the mean of its divisors is an integer number (35083776).

Almost surely, 2^139499609 is an apocalyptic number.

It is an amenable number.

139499609 is a deficient number, since it is larger than the sum of its proper divisors (835495).

139499609 is an equidigital number, since it uses as much as digits as its factorization.

139499609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 835494.

The product of its (nonzero) digits is 472392, while the sum is 50.

The square root of 139499609 is about 11810.9952586562. The cubic root of 139499609 is about 518.6300342128.

The spelling of 139499609 in words is "one hundred thirty-nine million, four hundred ninety-nine thousand, six hundred nine".