21311017463 has 4 divisors (see below), whose sum is σ = 21311364840. Its totient is φ = 21310670088.

The previous prime is 21311017373. The next prime is 21311017489. The reversal of 21311017463 is 36471011312.

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

It is a cyclic number.

It is not a de Polignac number, because 21311017463 - 2¹⁰ = 21311016439 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 (21311017493) 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, 54320 + ... + 213477.

It is an arithmetic number, because the mean of its divisors is an integer number (5327841210).

Almost surely, 2^21311017463 is an apocalyptic number.

21311017463 is a deficient number, since it is larger than the sum of its proper divisors (347377).

21311017463 is an equidigital number, since it uses as much as digits as its factorization.

21311017463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347376.

The product of its (nonzero) digits is 3024, while the sum is 29.

Adding to 21311017463 its reverse (36471011312), we get a palindrome (57782028775).

The spelling of 21311017463 in words is "twenty-one billion, three hundred eleven million, seventeen thousand, four hundred sixty-three".