21233548278 has 32 divisors (see below), whose sum is σ = 47219320800. Its totient is φ = 7072800768.

The previous prime is 21233548253. The next prime is 21233548279. The reversal of 21233548278 is 87284533212.

21233548278 is a `hidden beast` number, since 2 + 1 + 2 + 33 + 548 + 2 + 78 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233548279) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63451 + ... + 215622.

It is an arithmetic number, because the mean of its divisors is an integer number (1475603775).

Almost surely, 2^21233548278 is an apocalyptic number.

21233548278 is an abundant number, since it is smaller than the sum of its proper divisors (25985772522).

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

21233548278 is a wasteful number, since it uses less digits than its factorization.

21233548278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280493 (or 280487 counting only the distinct ones).

The product of its digits is 645120, while the sum is 45.

The spelling of 21233548278 in words is "twenty-one billion, two hundred thirty-three million, five hundred forty-eight thousand, two hundred seventy-eight".