20472649 has 4 divisors (see below), whose sum is σ = 20482000. Its totient is φ = 20463300.

The previous prime is 20472629. The next prime is 20472659. The reversal of 20472649 is 94627402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20472649 - 2²³ = 12084041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20472619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 574 + ... + 6424.

It is an arithmetic number, because the mean of its divisors is an integer number (5120500).

Almost surely, 2^20472649 is an apocalyptic number.

It is an amenable number.

20472649 is a deficient number, since it is larger than the sum of its proper divisors (9351).

20472649 is an equidigital number, since it uses as much as digits as its factorization.

20472649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9350.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 20472649 is about 4524.6711482714. The cubic root of 20472649 is about 273.5634130896.

The spelling of 20472649 in words is "twenty million, four hundred seventy-two thousand, six hundred forty-nine".