20351020505 has 8 divisors (see below), whose sum is σ = 24425031624. Its totient is φ = 16278278400.

The previous prime is 20351020477. The next prime is 20351020511. The reversal of 20351020505 is 50502015302.

It can be written as a sum of positive squares in 4 ways, for example, as 5337909721 + 15013110784 = 73061^2 + 122528^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-20351020505 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 281606 + ... + 346415.

It is an arithmetic number, because the mean of its divisors is an integer number (3053128953).

Almost surely, 2^20351020505 is an apocalyptic number.

It is an amenable number.

20351020505 is a deficient number, since it is larger than the sum of its proper divisors (4074011119).

20351020505 is an equidigital number, since it uses as much as digits as its factorization.

20351020505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 634507.

The product of its (nonzero) digits is 1500, while the sum is 23.

Adding to 20351020505 its reverse (50502015302), we get a palindrome (70853035807).

The spelling of 20351020505 in words is "twenty billion, three hundred fifty-one million, twenty thousand, five hundred five".