21409009076 has 96 divisors (see below), whose sum is σ = 48707248128. Its totient is φ = 8005495680.

The previous prime is 21409009049. The next prime is 21409009093. The reversal of 21409009076 is 67090090412.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 463151 + ... + 507273.

It is an arithmetic number, because the mean of its divisors is an integer number (507367168).

Almost surely, 2^21409009076 is an apocalyptic number.

21409009076 is a gapful number since it is divisible by the number (26) 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 21409009076, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24353624064).

21409009076 is an abundant number, since it is smaller than the sum of its proper divisors (27298239052).

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

21409009076 is a wasteful number, since it uses less digits than its factorization.

21409009076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44221 (or 44219 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 38.

Adding to 21409009076 its reverse (67090090412), we get a palindrome (88499099488).

The spelling of 21409009076 in words is "twenty-one billion, four hundred nine million, nine thousand, seventy-six".