221535211266640 has 40 divisors (see below), whose sum is σ = 519627502200168. Its totient is φ = 87829889064960.

The previous prime is 221535211266613. The next prime is 221535211266661. The reversal of 221535211266640 is 46662112535122.

It can be written as a sum of positive squares in 4 ways, for example, as 4163003638336 + 217372207628304 = 2040344^2 + 14743548^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12253044681 + ... + 12253062760.

Almost surely, 2^{221535211266640} is an apocalyptic number.

221535211266640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221535211266640 is an abundant number, since it is smaller than the sum of its proper divisors (298092290933528).

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

221535211266640 is a wasteful number, since it uses less digits than its factorization.

221535211266640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24506107567 (or 24506107561 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 46.

The spelling of 221535211266640 in words is "two hundred twenty-one trillion, five hundred thirty-five billion, two hundred eleven million, two hundred sixty-six thousand, six hundred forty".