21251773852 has 24 divisors (see below), whose sum is σ = 39714111360. Its totient is φ = 9928524480.

The previous prime is 21251773849. The next prime is 21251773859. The reversal of 21251773852 is 25837715212.

It is a junction number, because it is equal to n+sod(n) for n = 21251773799 and 21251773808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21251773859) 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, 2951323 + ... + 2958514.

It is an arithmetic number, because the mean of its divisors is an integer number (1654754640).

Almost surely, 2^21251773852 is an apocalyptic number.

It is an amenable number.

21251773852 is a deficient number, since it is larger than the sum of its proper divisors (18462337508).

21251773852 is a wasteful number, since it uses less digits than its factorization.

21251773852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5909901 (or 5909899 counting only the distinct ones).

The product of its digits is 235200, while the sum is 43.

The spelling of 21251773852 in words is "twenty-one billion, two hundred fifty-one million, seven hundred seventy-three thousand, eight hundred fifty-two".