21241617540 has 192 divisors, whose sum is σ = 70662170880. Its totient is φ = 4699791360.

The previous prime is 21241617499. The next prime is 21241617557. The reversal of 21241617540 is 4571614212.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 749712 + ... + 777528.

It is an arithmetic number, because the mean of its divisors is an integer number (368032140).

Almost surely, 2^21241617540 is an apocalyptic number.

21241617540 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 21241617540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35331085440).

21241617540 is an abundant number, since it is smaller than the sum of its proper divisors (49420553340).

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

21241617540 is a wasteful number, since it uses less digits than its factorization.

21241617540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27942 (or 27940 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The spelling of 21241617540 in words is "twenty-one billion, two hundred forty-one million, six hundred seventeen thousand, five hundred forty".