139426509 has 8 divisors (see below), whose sum is σ = 185976000. Its totient is φ = 92914016.

The previous prime is 139426489. The next prime is 139426523. The reversal of 139426509 is 905624931.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 139426509 - 2¹⁷ = 139295437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139426549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1249 + ... + 16745.

It is an arithmetic number, because the mean of its divisors is an integer number (23247000).

Almost surely, 2^139426509 is an apocalyptic number.

It is an amenable number.

139426509 is a deficient number, since it is larger than the sum of its proper divisors (46549491).

139426509 is a wasteful number, since it uses less digits than its factorization.

139426509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18499.

The product of its (nonzero) digits is 58320, while the sum is 39.

The square root of 139426509 is about 11807.9002790505. The cubic root of 139426509 is about 518.5394282729.

The spelling of 139426509 in words is "one hundred thirty-nine million, four hundred twenty-six thousand, five hundred nine".