20153809 has 8 divisors (see below), whose sum is σ = 21839552. Its totient is φ = 18487440.

The previous prime is 20153803. The next prime is 20153821. The reversal of 20153809 is 90835102.

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 20153809 - 2¹³ = 20145617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20153803) 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, 2637 + ... + 6874.

It is an arithmetic number, because the mean of its divisors is an integer number (2729944).

Almost surely, 2^20153809 is an apocalyptic number.

It is an amenable number.

20153809 is a deficient number, since it is larger than the sum of its proper divisors (1685743).

20153809 is a wasteful number, since it uses less digits than its factorization.

20153809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9687.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 20153809 is about 4489.2993885461. The cubic root of 20153809 is about 272.1358219086.

The spelling of 20153809 in words is "twenty million, one hundred fifty-three thousand, eight hundred nine".