20513347 has 4 divisors (see below), whose sum is σ = 20522736. Its totient is φ = 20503960.

The previous prime is 20513341. The next prime is 20513371. The reversal of 20513347 is 74331502.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20513347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20513341) 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, 498 + ... + 6424.

It is an arithmetic number, because the mean of its divisors is an integer number (5130684).

Almost surely, 2^20513347 is an apocalyptic number.

20513347 is a deficient number, since it is larger than the sum of its proper divisors (9389).

20513347 is an equidigital number, since it uses as much as digits as its factorization.

20513347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9388.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 20513347 is about 4529.1662588163. The cubic root of 20513347 is about 273.7445672142.

Adding to 20513347 its reverse (74331502), we get a palindrome (94844849).

The spelling of 20513347 in words is "twenty million, five hundred thirteen thousand, three hundred forty-seven".