20689667820 has 72 divisors (see below), whose sum is σ = 63074138400. Its totient is φ = 5489510400.

The previous prime is 20689667813. The next prime is 20689667827. The reversal of 20689667820 is 2876698602.

It is an interprime number because it is at equal distance from previous prime (20689667813) and next prime (20689667827).

It is not an unprimeable number, because it can be changed into a prime (20689667827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 252981 + ... + 324620.

It is an arithmetic number, because the mean of its divisors is an integer number (876029700).

Almost surely, 2^20689667820 is an apocalyptic number.

20689667820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20689667820 is an abundant number, since it is smaller than the sum of its proper divisors (42384470580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20689667820 is a wasteful number, since it uses less digits than its factorization.

20689667820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577815 (or 577810 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 20689667820 in words is "twenty billion, six hundred eighty-nine million, six hundred sixty-seven thousand, eight hundred twenty".