21851769396 has 24 divisors (see below), whose sum is σ = 51272313120. Its totient is φ = 7243230112.

The previous prime is 21851769377. The next prime is 21851769409. The reversal of 21851769396 is 69396715812.

It is a congruent number.

It is an unprimeable number.

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, 5084391 + ... + 5088686.

It is an arithmetic number, because the mean of its divisors is an integer number (2136346380).

Almost surely, 2^21851769396 is an apocalyptic number.

It is an amenable number.

21851769396 is an abundant number, since it is smaller than the sum of its proper divisors (29420543724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21851769396 is a wasteful number, since it uses less digits than its factorization.

21851769396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10173263 (or 10173261 counting only the distinct ones).

The product of its digits is 4898880, while the sum is 57.

The spelling of 21851769396 in words is "twenty-one billion, eight hundred fifty-one million, seven hundred sixty-nine thousand, three hundred ninety-six".