221731571512 has 128 divisors (see below), whose sum is σ = 471563389440. Its totient is φ = 96855022080.

The previous prime is 221731571497. The next prime is 221731571519. The reversal of 221731571512 is 215175137122.

It is a super-2 number, since 2×221731571512² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221731571519) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 186799383 + ... + 186800569.

It is an arithmetic number, because the mean of its divisors is an integer number (3684088980).

Almost surely, 2^221731571512 is an apocalyptic number.

221731571512 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 221731571512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235781694720).

221731571512 is an abundant number, since it is smaller than the sum of its proper divisors (249831817928).

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

221731571512 is a wasteful number, since it uses less digits than its factorization.

221731571512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1901 (or 1897 counting only the distinct ones).

The product of its digits is 29400, while the sum is 37.

The spelling of 221731571512 in words is "two hundred twenty-one billion, seven hundred thirty-one million, five hundred seventy-one thousand, five hundred twelve".