21161760516 has 192 divisors, whose sum is σ = 61167052800. Its totient is φ = 6283008000.

The previous prime is 21161760479. The next prime is 21161760523. The reversal of 21161760516 is 61506716112.

It is a happy number.

21161760516 is a `hidden beast` number, since 2 + 11 + 61 + 76 + 0 + 516 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 26157520 + ... + 26158328.

It is an arithmetic number, because the mean of its divisors is an integer number (318578400).

Almost surely, 2^21161760516 is an apocalyptic number.

21161760516 is a gapful number since it is divisible by the number (26) 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 21161760516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30583526400).

21161760516 is an abundant number, since it is smaller than the sum of its proper divisors (40005292284).

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

21161760516 is a wasteful number, since it uses less digits than its factorization.

21161760516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1467 (or 1459 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The spelling of 21161760516 in words is "twenty-one billion, one hundred sixty-one million, seven hundred sixty thousand, five hundred sixteen".