21013034240 has 216 divisors, whose sum is σ = 55673114784. Its totient is φ = 7593062400.

The previous prime is 21013034167. The next prime is 21013034293. The reversal of 21013034240 is 4243031012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32679359 + ... + 32680001.

Almost surely, 2^21013034240 is an apocalyptic number.

21013034240 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 21013034240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27836557392).

21013034240 is an abundant number, since it is smaller than the sum of its proper divisors (34660080544).

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

21013034240 is a wasteful number, since it uses less digits than its factorization.

21013034240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 897 (or 872 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21013034240 its reverse (4243031012), we get a palindrome (25256065252).

The spelling of 21013034240 in words is "twenty-one billion, thirteen million, thirty-four thousand, two hundred forty".