21161017152 has 448 divisors, whose sum is σ = 71688960000. Its totient is φ = 6058229760.

The previous prime is 21161017151. The next prime is 21161017169. The reversal of 21161017152 is 25171016112.

21161017152 is a `hidden beast` number, since 21 + 1 + 610 + 17 + 15 + 2 = 666.

It is a super-2 number, since 2×21161017152² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161017151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 42406599 + ... + 42407097.

It is an arithmetic number, because the mean of its divisors is an integer number (160020000).

Almost surely, 2^21161017152 is an apocalyptic number.

21161017152 is a gapful number since it is divisible by the number (22) 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 21161017152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35844480000).

21161017152 is an abundant number, since it is smaller than the sum of its proper divisors (50527942848).

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

21161017152 is a wasteful number, since it uses less digits than its factorization.

21161017152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651 (or 635 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 27.

The spelling of 21161017152 in words is "twenty-one billion, one hundred sixty-one million, seventeen thousand, one hundred fifty-two".