20870249 has 2 divisors, whose sum is σ = 20870250. Its totient is φ = 20870248.

The previous prime is 20870231. The next prime is 20870263. The reversal of 20870249 is 94207802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13542400 + 7327849 = 3680^2 + 2707^2 .

It is a cyclic number.

It is not a de Polignac number, because 20870249 - 2¹⁶ = 20804713 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20870219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435124 + 10435125.

It is an arithmetic number, because the mean of its divisors is an integer number (10435125).

Almost surely, 2^20870249 is an apocalyptic number.

It is an amenable number.

20870249 is a deficient number, since it is larger than the sum of its proper divisors (1).

20870249 is an equidigital number, since it uses as much as digits as its factorization.

20870249 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 20870249 is about 4568.3967647305. The cubic root of 20870249 is about 275.3230319684.

The spelling of 20870249 in words is "twenty million, eight hundred seventy thousand, two hundred forty-nine".