21051614416 has 240 divisors, whose sum is σ = 50930311680. Its totient is φ = 8390753280.

The previous prime is 21051614401. The next prime is 21051614417. The reversal of 21051614416 is 61441615012.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21051614417) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 75998470 + ... + 75998746.

It is an arithmetic number, because the mean of its divisors is an integer number (212209632).

Almost surely, 2^21051614416 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 21051614416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25465155840).

21051614416 is an abundant number, since it is smaller than the sum of its proper divisors (29878697264).

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

21051614416 is a wasteful number, since it uses less digits than its factorization.

21051614416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442 (or 429 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The spelling of 21051614416 in words is "twenty-one billion, fifty-one million, six hundred fourteen thousand, four hundred sixteen".