20408621809 has 8 divisors (see below), whose sum is σ = 21982920192. Its totient is φ = 18891570720.

The previous prime is 20408621759. The next prime is 20408621819. The reversal of 20408621809 is 90812680402.

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

It is not a de Polignac number, because 20408621809 - 2²⁹ = 19871750897 is a prime.

It is a super-4 number, since 4×20408621809⁴ (a number of 42 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20408621819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14311084 + ... + 14312509.

It is an arithmetic number, because the mean of its divisors is an integer number (2747865024).

Almost surely, 2^20408621809 is an apocalyptic number.

It is an amenable number.

20408621809 is a deficient number, since it is larger than the sum of its proper divisors (1574298383).

20408621809 is a wasteful number, since it uses less digits than its factorization.

20408621809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28623647.

The product of its (nonzero) digits is 55296, while the sum is 40.

The spelling of 20408621809 in words is "twenty billion, four hundred eight million, six hundred twenty-one thousand, eight hundred nine".