21110229978 has 192 divisors, whose sum is σ = 49197632256. Its totient is φ = 6003712000.

The previous prime is 21110229977. The next prime is 21110230007. The reversal of 21110229978 is 87992201112.

It is not an unprimeable number, because it can be changed into a prime (21110229977) 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 95 ways as a sum of consecutive naturals, for example, 209012128 + ... + 209012228.

It is an arithmetic number, because the mean of its divisors is an integer number (256237668).

Almost surely, 2^21110229978 is an apocalyptic number.

21110229978 is an abundant number, since it is smaller than the sum of its proper divisors (28087402278).

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

21110229978 is a wasteful number, since it uses less digits than its factorization.

21110229978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 42.

The spelling of 21110229978 in words is "twenty-one billion, one hundred ten million, two hundred twenty-nine thousand, nine hundred seventy-eight".