21533888517 has 8 divisors (see below), whose sum is σ = 28996127520. Its totient is φ = 14213787600.

The previous prime is 21533888503. The next prime is 21533888531. The reversal of 21533888517 is 71588833512.

It is an interprime number because it is at equal distance from previous prime (21533888503) and next prime (21533888531).

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

It is not a de Polignac number, because 21533888517 - 2⁸ = 21533888261 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21533888517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21533888417) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35534167 + ... + 35534772.

It is an arithmetic number, because the mean of its divisors is an integer number (3624515940).

Almost surely, 2^21533888517 is an apocalyptic number.

It is an amenable number.

21533888517 is a deficient number, since it is larger than the sum of its proper divisors (7462239003).

21533888517 is a wasteful number, since it uses less digits than its factorization.

21533888517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71069043.

The product of its digits is 1612800, while the sum is 51.

The spelling of 21533888517 in words is "twenty-one billion, five hundred thirty-three million, eight hundred eighty-eight thousand, five hundred seventeen".