20779543 has 2 divisors, whose sum is σ = 20779544. Its totient is φ = 20779542.

The previous prime is 20779531. The next prime is 20779547. The reversal of 20779543 is 34597702.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20779543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20779547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10389771 + 10389772.

It is an arithmetic number, because the mean of its divisors is an integer number (10389772).

Almost surely, 2^20779543 is an apocalyptic number.

20779543 is a deficient number, since it is larger than the sum of its proper divisors (1).

20779543 is an equidigital number, since it uses as much as digits as its factorization.

20779543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52920, while the sum is 37.

The square root of 20779543 is about 4558.4584016968. The cubic root of 20779543 is about 274.9235842776.

The spelling of 20779543 in words is "twenty million, seven hundred seventy-nine thousand, five hundred forty-three".