21436563231631 has 24 divisors (see below), whose sum is σ = 23683276360304. Its totient is φ = 19383332935680.

The previous prime is 21436563231593. The next prime is 21436563231637. The reversal of 21436563231631 is 13613236563412.

It is not a de Polignac number, because 21436563231631 - 2¹¹ = 21436563229583 is a prime.

It is a super-2 number, since 2×21436563231631² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21436563231637) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13381290 + ... + 14897383.

Almost surely, 2^{21436563231631} is an apocalyptic number.

21436563231631 is a deficient number, since it is larger than the sum of its proper divisors (2246713128673).

21436563231631 is a wasteful number, since it uses less digits than its factorization.

21436563231631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28278811 (or 28278794 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 46.

The spelling of 21436563231631 in words is "twenty-one trillion, four hundred thirty-six billion, five hundred sixty-three million, two hundred thirty-one thousand, six hundred thirty-one".