20506515506 has 8 divisors (see below), whose sum is σ = 32569171740. Its totient is φ = 9650124928.

The previous prime is 20506515493. The next prime is 20506515517. The reversal of 20506515506 is 60551560502.

It can be written as a sum of positive squares in 2 ways, for example, as 15628750225 + 4877765281 = 125015^2 + 69841^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 301566371 + ... + 301566438.

Almost surely, 2^20506515506 is an apocalyptic number.

20506515506 is a deficient number, since it is larger than the sum of its proper divisors (12062656234).

20506515506 is a wasteful number, since it uses less digits than its factorization.

20506515506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603132828.

The product of its (nonzero) digits is 45000, while the sum is 35.

The spelling of 20506515506 in words is "twenty billion, five hundred six million, five hundred fifteen thousand, five hundred six".