21504717378 has 40 divisors (see below), whose sum is σ = 48264567120. Its totient is φ = 7156625400.

The previous prime is 21504717371. The next prime is 21504717379. The reversal of 21504717378 is 87371740512.

21504717378 is a `hidden beast` number, since 2 + 1 + 504 + 7 + 1 + 73 + 78 = 666.

It is not an unprimeable number, because it can be changed into a prime (21504717371) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6948 + ... + 207503.

It is an arithmetic number, because the mean of its divisors is an integer number (1206614178).

Almost surely, 2^21504717378 is an apocalyptic number.

21504717378 is an abundant number, since it is smaller than the sum of its proper divisors (26759849742).

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

21504717378 is a wasteful number, since it uses less digits than its factorization.

21504717378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215084 (or 215075 counting only the distinct ones).

The product of its (nonzero) digits is 329280, while the sum is 45.

The spelling of 21504717378 in words is "twenty-one billion, five hundred four million, seven hundred seventeen thousand, three hundred seventy-eight".