20671409 has 8 divisors (see below), whose sum is σ = 22729728. Its totient is φ = 18642960.

The previous prime is 20671397. The next prime is 20671423. The reversal of 20671409 is 90417602.

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 20671409 - 2¹⁶ = 20605873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20671499) 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, 6002 + ... + 8795.

It is an arithmetic number, because the mean of its divisors is an integer number (2841216).

Almost surely, 2^20671409 is an apocalyptic number.

It is an amenable number.

20671409 is a deficient number, since it is larger than the sum of its proper divisors (2058319).

20671409 is a wasteful number, since it uses less digits than its factorization.

20671409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14935.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 20671409 is about 4546.5821228699. The cubic root of 20671409 is about 274.4458659699.

The spelling of 20671409 in words is "twenty million, six hundred seventy-one thousand, four hundred nine".