20870051 has 2 divisors, whose sum is σ = 20870052. Its totient is φ = 20870050.

The previous prime is 20870023. The next prime is 20870063. The reversal of 20870051 is 15007802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20870051 - 2⁶ = 20869987 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 20869999 and 20870026.

It is not a weakly prime, because it can be changed into another prime (20870071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435025 + 10435026.

It is an arithmetic number, because the mean of its divisors is an integer number (10435026).

Almost surely, 2^20870051 is an apocalyptic number.

20870051 is a deficient number, since it is larger than the sum of its proper divisors (1).

20870051 is an equidigital number, since it uses as much as digits as its factorization.

20870051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 20870051 is about 4568.3750940570. The cubic root of 20870051 is about 275.3221612851.

Adding to 20870051 its reverse (15007802), we get a palindrome (35877853).

The spelling of 20870051 in words is "twenty million, eight hundred seventy thousand, fifty-one".