20978273 has 2 divisors, whose sum is σ = 20978274. Its totient is φ = 20978272.

The previous prime is 20978267. The next prime is 20978311. The reversal of 20978273 is 37287902.

20978273 is an esthetic number in base 7, because in such base its adjacent digits differ by 1.

It is an a-pointer prime, because the next prime (20978311) can be obtained adding 20978273 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13454224 + 7524049 = 3668^2 + 2743^2 .

It is a cyclic number.

It is not a de Polignac number, because 20978273 - 2⁴ = 20978257 is a prime.

It is not a weakly prime, because it can be changed into another prime (20978233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10489136 + 10489137.

It is an arithmetic number, because the mean of its divisors is an integer number (10489137).

Almost surely, 2^20978273 is an apocalyptic number.

It is an amenable number.

20978273 is a deficient number, since it is larger than the sum of its proper divisors (1).

20978273 is an equidigital number, since it uses as much as digits as its factorization.

20978273 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 38.

The square root of 20978273 is about 4580.2044714183. The cubic root of 20978273 is about 275.7972369552.

The spelling of 20978273 in words is "twenty million, nine hundred seventy-eight thousand, two hundred seventy-three".