20988986971 has 2 divisors, whose sum is σ = 20988986972. Its totient is φ = 20988986970.

The previous prime is 20988986923. The next prime is 20988986989. The reversal of 20988986971 is 17968988902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20988986971 - 2¹⁹ = 20988462683 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20988986897 and 20988986906.

It is not a weakly prime, because it can be changed into another prime (20988986071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10494493485 + 10494493486.

It is an arithmetic number, because the mean of its divisors is an integer number (10494493486).

Almost surely, 2^20988986971 is an apocalyptic number.

20988986971 is a deficient number, since it is larger than the sum of its proper divisors (1).

20988986971 is an equidigital number, since it uses as much as digits as its factorization.

20988986971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31352832, while the sum is 67.

The spelling of 20988986971 in words is "twenty billion, nine hundred eighty-eight million, nine hundred eighty-six thousand, nine hundred seventy-one".