221479931520 has 768 divisors, whose sum is σ = 830988288000. Its totient is φ = 54195609600.

The previous prime is 221479931467. The next prime is 221479931521. The reversal of 221479931520 is 25139974122.

221479931520 is a `hidden beast` number, since 2 + 2 + 1 + 4 + 7 + 99 + 31 + 520 = 666.

It is a super-2 number, since 2×221479931520² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (221479931521) 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, 817268985 + ... + 817269255.

It is an arithmetic number, because the mean of its divisors is an integer number (1082016000).

Almost surely, 2^221479931520 is an apocalyptic number.

221479931520 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 221479931520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (415494144000).

221479931520 is an abundant number, since it is smaller than the sum of its proper divisors (609508356480).

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

221479931520 is a wasteful number, since it uses less digits than its factorization.

221479931520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549 (or 534 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The spelling of 221479931520 in words is "two hundred twenty-one billion, four hundred seventy-nine million, nine hundred thirty-one thousand, five hundred twenty".