20540997 has 6 divisors (see below), whose sum is σ = 29670342. Its totient is φ = 13693992.

The previous prime is 20540977. The next prime is 20540999. The reversal of 20540997 is 79904502.

20540997 is a `hidden beast` number, since 20 + 540 + 9 + 97 = 666.

It can be written as a sum of positive squares in only one way, i.e., 15163236 + 5377761 = 3894^2 + 2319^2 .

It is not a de Polignac number, because 20540997 - 2¹¹ = 20538949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20540999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1141158 + ... + 1141175.

It is an arithmetic number, because the mean of its divisors is an integer number (4945057).

Almost surely, 2^20540997 is an apocalyptic number.

It is an amenable number.

20540997 is a deficient number, since it is larger than the sum of its proper divisors (9129345).

20540997 is a wasteful number, since it uses less digits than its factorization.

20540997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2282339 (or 2282336 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 20540997 is about 4532.2176690887. The cubic root of 20540997 is about 273.8675056935.

The spelling of 20540997 in words is "twenty million, five hundred forty thousand, nine hundred ninety-seven".