21544471040 has 40 divisors (see below), whose sum is σ = 51656241780. Its totient is φ = 8617787392.

The previous prime is 21544471031. The next prime is 21544471049. The reversal of 21544471040 is 4017444512.

It is an interprime number because it is at equal distance from previous prime (21544471031) and next prime (21544471049).

It can be written as a sum of positive squares in 2 ways, for example, as 21540845824 + 3625216 = 146768^2 + 1904^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 21544470988 and 21544471006.

It is not an unprimeable number, because it can be changed into a prime (21544471049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4205345 + ... + 4210464.

Almost surely, 2^21544471040 is an apocalyptic number.

21544471040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21544471040 is an abundant number, since it is smaller than the sum of its proper divisors (30111770740).

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

21544471040 is an frugal number, since it uses more digits than its factorization.

21544471040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8415832 (or 8415816 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 32.

The spelling of 21544471040 in words is "twenty-one billion, five hundred forty-four million, four hundred seventy-one thousand, forty".