20081881557 has 16 divisors (see below), whose sum is σ = 29755327680. Its totient is φ = 13385944656.

The previous prime is 20081881541. The next prime is 20081881559. The reversal of 20081881557 is 75518818002.

20081881557 is a `hidden beast` number, since 2 + 0 + 0 + 8 + 18 + 81 + 557 = 666.

It is not a de Polignac number, because 20081881557 - 2⁴ = 20081881541 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 (20081881559) 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 15 ways as a sum of consecutive naturals, for example, 144558 + ... + 247104.

It is an arithmetic number, because the mean of its divisors is an integer number (1859707980).

Almost surely, 2^20081881557 is an apocalyptic number.

20081881557 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20081881557 is a deficient number, since it is larger than the sum of its proper divisors (9673446123).

20081881557 is a wasteful number, since it uses less digits than its factorization.

20081881557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109809 (or 109803 counting only the distinct ones).

The product of its (nonzero) digits is 179200, while the sum is 45.

The spelling of 20081881557 in words is "twenty billion, eighty-one million, eight hundred eighty-one thousand, five hundred fifty-seven".