1221543100493 has 2 divisors, whose sum is σ = 1221543100494. Its totient is φ = 1221543100492.

The previous prime is 1221543100441. The next prime is 1221543100507. The reversal of 1221543100493 is 3940013451221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 732219067204 + 489324033289 = 855698^2 + 699517^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221543100493 - 2²⁶ = 1221475991629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221543100423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610771550246 + 610771550247.

It is an arithmetic number, because the mean of its divisors is an integer number (610771550247).

Almost surely, 2^{1221543100493} is an apocalyptic number.

It is an amenable number.

1221543100493 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221543100493 is an equidigital number, since it uses as much as digits as its factorization.

1221543100493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 35.

The spelling of 1221543100493 in words is "one trillion, two hundred twenty-one billion, five hundred forty-three million, one hundred thousand, four hundred ninety-three".