221061240 has 96 divisors (see below), whose sum is σ = 722947680. Its totient is φ = 58580736.

The previous prime is 221061223. The next prime is 221061263. The reversal of 221061240 is 42160122.

221061240 is a `hidden beast` number, since 2 + 2 + 10 + 612 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 58282 + ... + 61958.

It is an arithmetic number, because the mean of its divisors is an integer number (7530705).

Almost surely, 2^221061240 is an apocalyptic number.

221061240 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 221061240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361473840).

221061240 is an abundant number, since it is smaller than the sum of its proper divisors (501886440).

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

221061240 is a wasteful number, since it uses less digits than its factorization.

221061240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3861 (or 3854 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 221061240 is about 14868.1283287440. The cubic root of 221061240 is about 604.6501996301.

The spelling of 221061240 in words is "two hundred twenty-one million, sixty-one thousand, two hundred forty".