20708971 has 2 divisors, whose sum is σ = 20708972. Its totient is φ = 20708970.

The previous prime is 20708969. The next prime is 20709041. The reversal of 20708971 is 17980702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20708971 - 2¹ = 20708969 is a prime.

It is a super-2 number, since 2×20708971² = 857722959757682, which contains 22 as substring.

Together with 20708969, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20708911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10354485 + 10354486.

It is an arithmetic number, because the mean of its divisors is an integer number (10354486).

Almost surely, 2^20708971 is an apocalyptic number.

20708971 is a deficient number, since it is larger than the sum of its proper divisors (1).

20708971 is an equidigital number, since it uses as much as digits as its factorization.

20708971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 34.

The square root of 20708971 is about 4550.7110433426. The cubic root of 20708971 is about 274.6119971694.

The spelling of 20708971 in words is "twenty million, seven hundred eight thousand, nine hundred seventy-one".