21900856237 has 8 divisors (see below), whose sum is σ = 24972922296. Its totient is φ = 19026988032.

The previous prime is 21900856213. The next prime is 21900856253. The reversal of 21900856237 is 73265800912.

It can be written as a sum of positive squares in 4 ways, for example, as 8083088836 + 13817767401 = 89906^2 + 117549^2 .

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

It is not a de Polignac number, because 21900856237 - 2¹¹ = 21900854189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21900856193 and 21900856202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21900856267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49549228 + ... + 49549669.

It is an arithmetic number, because the mean of its divisors is an integer number (3121615287).

Almost surely, 2^21900856237 is an apocalyptic number.

It is an amenable number.

21900856237 is a deficient number, since it is larger than the sum of its proper divisors (3072066059).

21900856237 is a wasteful number, since it uses less digits than its factorization.

21900856237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99098927.

The product of its (nonzero) digits is 181440, while the sum is 43.

The spelling of 21900856237 in words is "twenty-one billion, nine hundred million, eight hundred fifty-six thousand, two hundred thirty-seven".