21015416736 has 192 divisors, whose sum is σ = 63097574400. Its totient is φ = 6802069248.

The previous prime is 21015416729. The next prime is 21015416743. The reversal of 21015416736 is 63761451012.

21015416736 is a `hidden beast` number, since 2 + 101 + 541 + 6 + 7 + 3 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (21015416729) and next prime (21015416743).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21015416736.

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, 4228525 + ... + 4233491.

It is an arithmetic number, because the mean of its divisors is an integer number (328633200).

Almost surely, 2^21015416736 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21015416736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31548787200).

21015416736 is an abundant number, since it is smaller than the sum of its proper divisors (42082157664).

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

21015416736 is a wasteful number, since it uses less digits than its factorization.

21015416736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5128 (or 5114 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

Adding to 21015416736 its reverse (63761451012), we get a palindrome (84776867748).

The spelling of 21015416736 in words is "twenty-one billion, fifteen million, four hundred sixteen thousand, seven hundred thirty-six".