20867971 has 2 divisors, whose sum is σ = 20867972. Its totient is φ = 20867970.

The previous prime is 20867933. The next prime is 20867981. The reversal of 20867971 is 17976802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20867971 - 2⁷ = 20867843 is a prime.

It is not a weakly prime, because it can be changed into another prime (20867911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10433985 + 10433986.

It is an arithmetic number, because the mean of its divisors is an integer number (10433986).

Almost surely, 2^20867971 is an apocalyptic number.

20867971 is a deficient number, since it is larger than the sum of its proper divisors (1).

20867971 is an equidigital number, since it uses as much as digits as its factorization.

20867971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 20867971 is about 4568.1474363247. The cubic root of 20867971 is about 275.3130143801.

The spelling of 20867971 in words is "twenty million, eight hundred sixty-seven thousand, nine hundred seventy-one".