20988987001 has 2 divisors, whose sum is σ = 20988987002. Its totient is φ = 20988987000.

The previous prime is 20988986989. The next prime is 20988987023. The reversal of 20988987001 is 10078988902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20470741776 + 518245225 = 143076^2 + 22765^2 .

It is a cyclic number.

It is not a de Polignac number, because 20988987001 - 2¹⁷ = 20988855929 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20988987001.

It is not a weakly prime, because it can be changed into another prime (20988987031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10494493500 + 10494493501.

It is an arithmetic number, because the mean of its divisors is an integer number (10494493501).

Almost surely, 2^20988987001 is an apocalyptic number.

It is an amenable number.

20988987001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20988987001 is an equidigital number, since it uses as much as digits as its factorization.

20988987001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 580608, while the sum is 52.

The spelling of 20988987001 in words is "twenty billion, nine hundred eighty-eight million, nine hundred eighty-seven thousand, one".