20472665 has 4 divisors (see below), whose sum is σ = 24567204. Its totient is φ = 16378128.

The previous prime is 20472659. The next prime is 20472703. The reversal of 20472665 is 56627402.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14992384 + 5480281 = 3872^2 + 2341^2 .

It is a cyclic number.

It is not a de Polignac number, because 20472665 - 2¹⁶ = 20407129 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2047262 + ... + 2047271.

It is an arithmetic number, because the mean of its divisors is an integer number (6141801).

Almost surely, 2^20472665 is an apocalyptic number.

It is an amenable number.

20472665 is a deficient number, since it is larger than the sum of its proper divisors (4094539).

20472665 is an equidigital number, since it uses as much as digits as its factorization.

20472665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4094538.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 20472665 is about 4524.6729163554. The cubic root of 20472665 is about 273.5634843556.

The spelling of 20472665 in words is "twenty million, four hundred seventy-two thousand, six hundred sixty-five".