21800157833 has 4 divisors (see below), whose sum is σ = 21800460948. Its totient is φ = 21799854720.

The previous prime is 21800157811. The next prime is 21800157839. The reversal of 21800157833 is 33875100812.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2614583689 + 19185574144 = 51133^2 + 138512^2 .

It is a cyclic number.

It is not a de Polignac number, because 21800157833 - 2¹⁰ = 21800156809 is a prime.

It is a super-2 number, since 2×21800157833² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21800157839) 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, 24485 + ... + 210237.

It is an arithmetic number, because the mean of its divisors is an integer number (5450115237).

Almost surely, 2^21800157833 is an apocalyptic number.

It is an amenable number.

21800157833 is a deficient number, since it is larger than the sum of its proper divisors (303115).

21800157833 is a wasteful number, since it uses less digits than its factorization.

21800157833 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303114.

The product of its (nonzero) digits is 40320, while the sum is 38.

The spelling of 21800157833 in words is "twenty-one billion, eight hundred million, one hundred fifty-seven thousand, eight hundred thirty-three".