20516633280 has 672 divisors, whose sum is σ = 85633486848. Its totient is φ = 4440268800.

The previous prime is 20516633231. The next prime is 20516633281. The reversal of 20516633280 is 8233661502.

It is a happy number.

20516633280 is a `hidden beast` number, since 2 + 0 + 5 + 16 + 633 + 2 + 8 + 0 = 666.

It is a super-2 number, since 2×20516633280² (a number of 21 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (20516633281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 12766237 + ... + 12767843.

It is an arithmetic number, because the mean of its divisors is an integer number (127430784).

Almost surely, 2^20516633280 is an apocalyptic number.

20516633280 is a gapful number since it is divisible by the number (20) 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 20516633280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42816743424).

20516633280 is an abundant number, since it is smaller than the sum of its proper divisors (65116853568).

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

20516633280 is a wasteful number, since it uses less digits than its factorization.

20516633280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1685 (or 1672 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

It can be divided in two parts, 20516 and 633280, that added together give a triangular number (653796 = T₁₁₄₃).

The spelling of 20516633280 in words is "twenty billion, five hundred sixteen million, six hundred thirty-three thousand, two hundred eighty".