20471664449 has 4 divisors (see below), whose sum is σ = 20970973380. Its totient is φ = 19972355520.

The previous prime is 20471664431. The next prime is 20471664467. The reversal of 20471664449 is 94446617402.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (20471664431) and next prime (20471664467).

It can be written as a sum of positive squares in 2 ways, for example, as 12049013824 + 8422650625 = 109768^2 + 91775^2 .

It is a cyclic number.

It is not a de Polignac number, because 20471664449 - 2⁸ = 20471664193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20479664449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 249654404 + ... + 249654485.

It is an arithmetic number, because the mean of its divisors is an integer number (5242743345).

Almost surely, 2^20471664449 is an apocalyptic number.

It is an amenable number.

20471664449 is a deficient number, since it is larger than the sum of its proper divisors (499308931).

20471664449 is an equidigital number, since it uses as much as digits as its factorization.

20471664449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499308930.

The product of its (nonzero) digits is 1161216, while the sum is 47.

The spelling of 20471664449 in words is "twenty billion, four hundred seventy-one million, six hundred sixty-four thousand, four hundred forty-nine".