20781367 has 2 divisors, whose sum is σ = 20781368. Its totient is φ = 20781366.

The previous prime is 20781349. The next prime is 20781389. The reversal of 20781367 is 76318702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20781367 - 2⁷ = 20781239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20781337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10390683 + 10390684.

It is an arithmetic number, because the mean of its divisors is an integer number (10390684).

Almost surely, 2^20781367 is an apocalyptic number.

20781367 is a deficient number, since it is larger than the sum of its proper divisors (1).

20781367 is an equidigital number, since it uses as much as digits as its factorization.

20781367 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 20781367 is about 4558.6584649434. The cubic root of 20781367 is about 274.9316281815.

The spelling of 20781367 in words is "twenty million, seven hundred eighty-one thousand, three hundred sixty-seven".