20540355697 has 2 divisors, whose sum is σ = 20540355698. Its totient is φ = 20540355696.

The previous prime is 20540355673. The next prime is 20540355739. The reversal of 20540355697 is 79655304502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15156318321 + 5384037376 = 123111^2 + 73376^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20540355697 is a prime.

It is not a weakly prime, because it can be changed into another prime (20540355097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10270177848 + 10270177849.

It is an arithmetic number, because the mean of its divisors is an integer number (10270177849).

Almost surely, 2^20540355697 is an apocalyptic number.

It is an amenable number.

20540355697 is a deficient number, since it is larger than the sum of its proper divisors (1).

20540355697 is an equidigital number, since it uses as much as digits as its factorization.

20540355697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1134000, while the sum is 46.

The spelling of 20540355697 in words is "twenty billion, five hundred forty million, three hundred fifty-five thousand, six hundred ninety-seven".