21858517124399 has 8 divisors (see below), whose sum is σ = 21876568890000. Its totient is φ = 21840466242816.

The previous prime is 21858517124393. The next prime is 21858517124417. The reversal of 21858517124399 is 99342171585812.

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

It is a cyclic number.

It is not a de Polignac number, because 21858517124399 - 2⁴ = 21858517124383 is a prime.

It is a super-2 number, since 2×21858517124399² (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 (21858517124393) 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, 54911309 + ... + 55307945.

It is an arithmetic number, because the mean of its divisors is an integer number (2734571111250).

Almost surely, 2^{21858517124399} is an apocalyptic number.

21858517124399 is a deficient number, since it is larger than the sum of its proper divisors (18051765601).

21858517124399 is a wasteful number, since it uses less digits than its factorization.

21858517124399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442009.

The product of its digits is 43545600, while the sum is 65.

The spelling of 21858517124399 in words is "twenty-one trillion, eight hundred fifty-eight billion, five hundred seventeen million, one hundred twenty-four thousand, three hundred ninety-nine".