221524243650421 has 2 divisors, whose sum is σ = 221524243650422. Its totient is φ = 221524243650420.

The previous prime is 221524243650401. The next prime is 221524243650503. The reversal of 221524243650421 is 124056342425122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 215233106180625 + 6291137469796 = 14670825^2 + 2508214^2 .

It is a cyclic number.

It is not a de Polignac number, because 221524243650421 - 2¹⁷ = 221524243519349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221524243650401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110762121825210 + 110762121825211.

It is an arithmetic number, because the mean of its divisors is an integer number (110762121825211).

Almost surely, 2^{221524243650421} is an apocalyptic number.

It is an amenable number.

221524243650421 is a deficient number, since it is larger than the sum of its proper divisors (1).

221524243650421 is an equidigital number, since it uses as much as digits as its factorization.

221524243650421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 921600, while the sum is 43.

The spelling of 221524243650421 in words is "two hundred twenty-one trillion, five hundred twenty-four billion, two hundred forty-three million, six hundred fifty thousand, four hundred twenty-one".