20298509851 has 4 divisors (see below), whose sum is σ = 20310673600. Its totient is φ = 20286346104.

The previous prime is 20298509831. The next prime is 20298509857. The reversal of 20298509851 is 15890589202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15890589202 = 2 ⋅7945294601.

It is a cyclic number.

It is not a de Polignac number, because 20298509851 - 2¹⁵ = 20298477083 is a prime.

It is a super-2 number, since 2×20298509851² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20298509795 and 20298509804.

It is not an unprimeable number, because it can be changed into a prime (20298509857) 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 in 3 ways as a sum of consecutive naturals, for example, 6079371 + ... + 6082708.

It is an arithmetic number, because the mean of its divisors is an integer number (5077668400).

Almost surely, 2^20298509851 is an apocalyptic number.

20298509851 is a deficient number, since it is larger than the sum of its proper divisors (12163749).

20298509851 is a wasteful number, since it uses less digits than its factorization.

20298509851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12163748.

The product of its (nonzero) digits is 518400, while the sum is 49.

The spelling of 20298509851 in words is "twenty billion, two hundred ninety-eight million, five hundred nine thousand, eight hundred fifty-one".