21116405360 has 80 divisors (see below), whose sum is σ = 49838810112. Its totient is φ = 8318956800.

The previous prime is 21116405351. The next prime is 21116405369. The reversal of 21116405360 is 6350461112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21116405351) and next prime (21116405369).

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21116405369) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10626287 + ... + 10628273.

Almost surely, 2^21116405360 is an apocalyptic number.

21116405360 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 21116405360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24919405056).

21116405360 is an abundant number, since it is smaller than the sum of its proper divisors (28722404752).

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

21116405360 is a wasteful number, since it uses less digits than its factorization.

21116405360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3942 (or 3936 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

Adding to 21116405360 its reverse (6350461112), we get a palindrome (27466866472).

The spelling of 21116405360 in words is "twenty-one billion, one hundred sixteen million, four hundred five thousand, three hundred sixty".