16215181220 has 192 divisors, whose sum is σ = 41319936000. Its totient is φ = 5228084736.

The previous prime is 16215181211. The next prime is 16215181231. The reversal of 16215181220 is 2218151261.

16215181220 = T₁₅₂₀₅ + T₁₅₂₀₆ + ... + T₁₅₃₄₃.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 33295817 + ... + 33296303.

It is an arithmetic number, because the mean of its divisors is an integer number (215208000).

Almost surely, 2^16215181220 is an apocalyptic number.

16215181220 is a gapful number since it is divisible by the number (10) 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 16215181220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20659968000).

16215181220 is an abundant number, since it is smaller than the sum of its proper divisors (25104754780).

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

16215181220 is a wasteful number, since it uses less digits than its factorization.

16215181220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730 (or 728 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 29.

The spelling of 16215181220 in words is "sixteen billion, two hundred fifteen million, one hundred eighty-one thousand, two hundred twenty".