21978258328 has 32 divisors (see below), whose sum is σ = 44434202400. Its totient is φ = 10131234048.

The previous prime is 21978258301. The next prime is 21978258329. The reversal of 21978258328 is 82385287912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21978258329) 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, 46476 + ... + 214747.

It is an arithmetic number, because the mean of its divisors is an integer number (1388568825).

Almost surely, 2^21978258328 is an apocalyptic number.

It is an amenable number.

21978258328 is an abundant number, since it is smaller than the sum of its proper divisors (22455944072).

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

21978258328 is a wasteful number, since it uses less digits than its factorization.

21978258328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262051 (or 262047 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 55.

The spelling of 21978258328 in words is "twenty-one billion, nine hundred seventy-eight million, two hundred fifty-eight thousand, three hundred twenty-eight".