20471664451 has 4 divisors (see below), whose sum is σ = 23396187952. Its totient is φ = 17547140952.

The previous prime is 20471664431. The next prime is 20471664467. The reversal of 20471664451 is 15446617402.

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

It is a cyclic number.

It is not a de Polignac number, because 20471664451 - 2⁹ = 20471663939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20471664431) 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, 1462261740 + ... + 1462261753.

It is an arithmetic number, because the mean of its divisors is an integer number (5849046988).

Almost surely, 2^20471664451 is an apocalyptic number.

20471664451 is a deficient number, since it is larger than the sum of its proper divisors (2924523501).

20471664451 is an equidigital number, since it uses as much as digits as its factorization.

20471664451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2924523500.

The product of its (nonzero) digits is 161280, while the sum is 40.

The spelling of 20471664451 in words is "twenty billion, four hundred seventy-one million, six hundred sixty-four thousand, four hundred fifty-one".