20971507 has 2 divisors, whose sum is σ = 20971508. Its totient is φ = 20971506.

The previous prime is 20971493. The next prime is 20971529. The reversal of 20971507 is 70517902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20971507 - 2¹⁵ = 20938739 is a prime.

It is not a weakly prime, because it can be changed into another prime (20971537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10485753 + 10485754.

It is an arithmetic number, because the mean of its divisors is an integer number (10485754).

Almost surely, 2^20971507 is an apocalyptic number.

20971507 is a deficient number, since it is larger than the sum of its proper divisors (1).

20971507 is an equidigital number, since it uses as much as digits as its factorization.

20971507 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4410, while the sum is 31.

The square root of 20971507 is about 4579.4657985403. The cubic root of 20971507 is about 275.7675833424.

The spelling of 20971507 in words is "twenty million, nine hundred seventy-one thousand, five hundred seven".