20471513 has 4 divisors (see below), whose sum is σ = 20701620. Its totient is φ = 20241408.

The previous prime is 20471497. The next prime is 20471579. The reversal of 20471513 is 31517402.

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 13778944 + 6692569 = 3712^2 + 2587^2 .

It is a cyclic number.

It is not a de Polignac number, because 20471513 - 2⁴ = 20471497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20471413) 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, 114920 + ... + 115097.

It is an arithmetic number, because the mean of its divisors is an integer number (5175405).

Almost surely, 2^20471513 is an apocalyptic number.

It is an amenable number.

20471513 is a deficient number, since it is larger than the sum of its proper divisors (230107).

20471513 is an equidigital number, since it uses as much as digits as its factorization.

20471513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230106.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 20471513 is about 4524.5456125450. The cubic root of 20471513 is about 273.5583531063.

Adding to 20471513 its reverse (31517402), we get a palindrome (51988915).

It can be divided in two parts, 204 and 71513, that added together give a palindrome (71717).

The spelling of 20471513 in words is "twenty million, four hundred seventy-one thousand, five hundred thirteen".