20651748505 has 8 divisors (see below), whose sum is σ = 25451884872. Its totient is φ = 16074874368.

The previous prime is 20651748479. The next prime is 20651748521. The reversal of 20651748505 is 50584715602.

It can be written as a sum of positive squares in 4 ways, for example, as 7464441609 + 13187306896 = 86397^2 + 114836^2 .

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

It is not a de Polignac number, because 20651748505 - 2¹⁷ = 20651617433 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, 55815352 + ... + 55815721.

It is an arithmetic number, because the mean of its divisors is an integer number (3181485609).

Almost surely, 2^20651748505 is an apocalyptic number.

It is an amenable number.

20651748505 is a deficient number, since it is larger than the sum of its proper divisors (4800136367).

20651748505 is a wasteful number, since it uses less digits than its factorization.

20651748505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111631115.

The product of its (nonzero) digits is 336000, while the sum is 43.

The spelling of 20651748505 in words is "twenty billion, six hundred fifty-one million, seven hundred forty-eight thousand, five hundred five".