20001657541 has 4 divisors (see below), whose sum is σ = 20691369900. Its totient is φ = 19311945184.

The previous prime is 20001657539. The next prime is 20001657551. The reversal of 20001657541 is 14575610002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11927916225 + 8073741316 = 109215^2 + 89854^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001657541 - 2¹ = 20001657539 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001657551) 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 3 ways as a sum of consecutive naturals, for example, 344856136 + ... + 344856193.

It is an arithmetic number, because the mean of its divisors is an integer number (5172842475).

Almost surely, 2^20001657541 is an apocalyptic number.

It is an amenable number.

20001657541 is a deficient number, since it is larger than the sum of its proper divisors (689712359).

20001657541 is an equidigital number, since it uses as much as digits as its factorization.

20001657541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 689712358.

The product of its (nonzero) digits is 8400, while the sum is 31.

The spelling of 20001657541 in words is "twenty billion, one million, six hundred fifty-seven thousand, five hundred forty-one".