20309864602 has 4 divisors (see below), whose sum is σ = 30464796906. Its totient is φ = 10154932300.

The previous prime is 20309864599. The next prime is 20309864609. The reversal of 20309864602 is 20646890302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20646890302 = 2 ⋅10323445151.

It can be written as a sum of positive squares in only one way, i.e., 17569237401 + 2740627201 = 132549^2 + 52351^2 .

It is not an unprimeable number, because it can be changed into a prime (20309864609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5077466149 + ... + 5077466152.

Almost surely, 2^20309864602 is an apocalyptic number.

20309864602 is a deficient number, since it is larger than the sum of its proper divisors (10154932304).

20309864602 is a wasteful number, since it uses less digits than its factorization.

20309864602 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10154932303.

The product of its (nonzero) digits is 124416, while the sum is 40.

The spelling of 20309864602 in words is "twenty billion, three hundred nine million, eight hundred sixty-four thousand, six hundred two".