21615211140 has 24 divisors (see below), whose sum is σ = 60522591360. Its totient is φ = 5764056288.

The previous prime is 21615211139. The next prime is 21615211199. The reversal of 21615211140 is 4111251612.

It is a self number, because there is not a number n which added to its sum of digits gives 21615211140.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180126700 + ... + 180126819.

It is an arithmetic number, because the mean of its divisors is an integer number (2521774640).

Almost surely, 2^21615211140 is an apocalyptic number.

21615211140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21615211140 is an abundant number, since it is smaller than the sum of its proper divisors (38907380220).

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

21615211140 is a wasteful number, since it uses less digits than its factorization.

21615211140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360253531 (or 360253529 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 24.

Adding to 21615211140 its reverse (4111251612), we get a palindrome (25726462752).

The spelling of 21615211140 in words is "twenty-one billion, six hundred fifteen million, two hundred eleven thousand, one hundred forty".