21070851984 has 240 divisors, whose sum is σ = 73574929792. Its totient is φ = 5480773632.

The previous prime is 21070851947. The next prime is 21070852013. The reversal of 21070851984 is 48915807012.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 945579 + ... + 967605.

Almost surely, 2^21070851984 is an apocalyptic number.

21070851984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21070851984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36787464896).

21070851984 is an abundant number, since it is smaller than the sum of its proper divisors (52504077808).

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

21070851984 is a wasteful number, since it uses less digits than its factorization.

21070851984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22134 (or 22125 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 21070851984 in words is "twenty-one billion, seventy million, eight hundred fifty-one thousand, nine hundred eighty-four".