19138909 has 8 divisors (see below), whose sum is σ = 20196000. Its totient is φ = 18086832.

The previous prime is 19138897. The next prime is 19138919. The reversal of 19138909 is 90983191.

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 19138909 - 2⁵ = 19138877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19138919) 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, 8682 + ... + 10660.

It is an arithmetic number, because the mean of its divisors is an integer number (2524500).

Almost surely, 2^19138909 is an apocalyptic number.

19138909 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

19138909 is a deficient number, since it is larger than the sum of its proper divisors (1057091).

19138909 is a wasteful number, since it uses less digits than its factorization.

19138909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2507.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 19138909 is about 4374.8038813186. The cubic root of 19138909 is about 267.4888760041.

The spelling of 19138909 in words is "nineteen million, one hundred thirty-eight thousand, nine hundred nine".