21727248840 has 480 divisors, whose sum is σ = 81010230840. Its totient is φ = 5218836480.

The previous prime is 21727248797. The next prime is 21727248841. The reversal of 21727248840 is 4884272712.

It can be written as a sum of positive squares in 4 ways, for example, as 14444674596 + 7282574244 = 120186^2 + 85338^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (21727248841) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 61550104 + ... + 61550456.

Almost surely, 2^21727248840 is an apocalyptic number.

21727248840 is a gapful number since it is divisible by the number (20) 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 21727248840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40505115420).

21727248840 is an abundant number, since it is smaller than the sum of its proper divisors (59282982000).

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

21727248840 is a wasteful number, since it uses less digits than its factorization.

21727248840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555 (or 531 counting only the distinct ones).

The product of its (nonzero) digits is 401408, while the sum is 45.

The spelling of 21727248840 in words is "twenty-one billion, seven hundred twenty-seven million, two hundred forty-eight thousand, eight hundred forty".