20587988081 has 2 divisors, whose sum is σ = 20587988082. Its totient is φ = 20587988080.

The previous prime is 20587988077. The next prime is 20587988123. The reversal of 20587988081 is 18088978502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18906250000 + 1681738081 = 137500^2 + 41009^2 .

It is a cyclic number.

It is not a de Polignac number, because 20587988081 - 2² = 20587988077 is a prime.

It is a super-2 number, since 2×20587988081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20587988051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10293994040 + 10293994041.

It is an arithmetic number, because the mean of its divisors is an integer number (10293994041).

Almost surely, 2^20587988081 is an apocalyptic number.

It is an amenable number.

20587988081 is a deficient number, since it is larger than the sum of its proper divisors (1).

20587988081 is an equidigital number, since it uses as much as digits as its factorization.

20587988081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2580480, while the sum is 56.

The spelling of 20587988081 in words is "twenty billion, five hundred eighty-seven million, nine hundred eighty-eight thousand, eighty-one".