21284631057541 has 4 divisors (see below), whose sum is σ = 21439993328172. Its totient is φ = 21129268786912.

The previous prime is 21284631057539. The next prime is 21284631057551. The reversal of 21284631057541 is 14575013648212.

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 6066635006916 + 15217996050625 = 2463054^2 + 3901025^2 .

It is a cyclic number.

It is not a de Polignac number, because 21284631057541 - 2¹ = 21284631057539 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 (21284631057551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77681135110 + ... + 77681135383.

It is an arithmetic number, because the mean of its divisors is an integer number (5359998332043).

Almost surely, 2^{21284631057541} is an apocalyptic number.

It is an amenable number.

21284631057541 is a deficient number, since it is larger than the sum of its proper divisors (155362270631).

21284631057541 is a wasteful number, since it uses less digits than its factorization.

21284631057541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155362270630.

The product of its (nonzero) digits is 1612800, while the sum is 49.

The spelling of 21284631057541 in words is "twenty-one trillion, two hundred eighty-four billion, six hundred thirty-one million, fifty-seven thousand, five hundred forty-one".