21436517023 has 8 divisors (see below), whose sum is σ = 21802152960. Its totient is φ = 21070958040.

The previous prime is 21436516973. The next prime is 21436517059. The reversal of 21436517023 is 32071563412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21436517023 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21436517023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21436517623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 982236 + ... + 1003822.

It is an arithmetic number, because the mean of its divisors is an integer number (2725269120).

Almost surely, 2^21436517023 is an apocalyptic number.

21436517023 is a deficient number, since it is larger than the sum of its proper divisors (365635937).

21436517023 is a wasteful number, since it uses less digits than its factorization.

21436517023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38477.

The product of its (nonzero) digits is 30240, while the sum is 34.

The spelling of 21436517023 in words is "twenty-one billion, four hundred thirty-six million, five hundred seventeen thousand, twenty-three".