20897641609 has 8 divisors (see below), whose sum is σ = 22599319680. Its totient is φ = 19209416016.

The previous prime is 20897641591. The next prime is 20897641613. The reversal of 20897641609 is 90614679802.

It is a happy number.

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 20897641609 - 2⁵ = 20897641577 is a prime.

It is a super-2 number, since 2×20897641609² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20897641669) 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, 3359887 + ... + 3366100.

It is an arithmetic number, because the mean of its divisors is an integer number (2824914960).

Almost surely, 2^20897641609 is an apocalyptic number.

It is an amenable number.

20897641609 is a deficient number, since it is larger than the sum of its proper divisors (1701678071).

20897641609 is a wasteful number, since it uses less digits than its factorization.

20897641609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6726239.

The product of its (nonzero) digits is 1306368, while the sum is 52.

The spelling of 20897641609 in words is "twenty billion, eight hundred ninety-seven million, six hundred forty-one thousand, six hundred nine".