20680808157 has 12 divisors (see below), whose sum is σ = 30679637820. Its totient is φ = 13414578048.

The previous prime is 20680808149. The next prime is 20680808171. The reversal of 20680808157 is 75180808602.

It can be written as a sum of positive squares in 2 ways, for example, as 10963974681 + 9716833476 = 104709^2 + 98574^2 .

It is not a de Polignac number, because 20680808157 - 2³ = 20680808149 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20680808117) 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 11 ways as a sum of consecutive naturals, for example, 31051932 + ... + 31052597.

It is an arithmetic number, because the mean of its divisors is an integer number (2556636485).

Almost surely, 2^20680808157 is an apocalyptic number.

It is an amenable number.

20680808157 is a deficient number, since it is larger than the sum of its proper divisors (9998829663).

20680808157 is a wasteful number, since it uses less digits than its factorization.

20680808157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62104572 (or 62104569 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 45.

The spelling of 20680808157 in words is "twenty billion, six hundred eighty million, eight hundred eight thousand, one hundred fifty-seven".