221181251640 has 64 divisors (see below), whose sum is σ = 663613292160. Its totient is φ = 58975486080.

The previous prime is 221181251587. The next prime is 221181251663. The reversal of 221181251640 is 46152181122.

221181251640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221181251640² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1116495 + ... + 1299585.

It is an arithmetic number, because the mean of its divisors is an integer number (10368957690).

Almost surely, 2^221181251640 is an apocalyptic number.

221181251640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221181251640 is an abundant number, since it is smaller than the sum of its proper divisors (442432040520).

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

221181251640 is a wasteful number, since it uses less digits than its factorization.

221181251640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193172 (or 193168 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The spelling of 221181251640 in words is "two hundred twenty-one billion, one hundred eighty-one million, two hundred fifty-one thousand, six hundred forty".