20805067457 has 2 divisors, whose sum is σ = 20805067458. Its totient is φ = 20805067456.

The previous prime is 20805067447. The next prime is 20805067489. The reversal of 20805067457 is 75476050802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20236769536 + 568297921 = 142256^2 + 23839^2 .

It is a cyclic number.

It is not a de Polignac number, because 20805067457 - 2⁴ = 20805067441 is a prime.

It is not a weakly prime, because it can be changed into another prime (20805067447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10402533728 + 10402533729.

It is an arithmetic number, because the mean of its divisors is an integer number (10402533729).

Almost surely, 2^20805067457 is an apocalyptic number.

It is an amenable number.

20805067457 is a deficient number, since it is larger than the sum of its proper divisors (1).

20805067457 is an equidigital number, since it uses as much as digits as its factorization.

20805067457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 470400, while the sum is 44.

The spelling of 20805067457 in words is "twenty billion, eight hundred five million, sixty-seven thousand, four hundred fifty-seven".