1221527141 has 2 divisors, whose sum is σ = 1221527142. Its totient is φ = 1221527140.

The previous prime is 1221527137. The next prime is 1221527143. The reversal of 1221527141 is 1417251221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1218708100 + 2819041 = 34910^2 + 1679^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221527141 - 2² = 1221527137 is a prime.

Together with 1221527143, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221527141.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221527143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610763570 + 610763571.

It is an arithmetic number, because the mean of its divisors is an integer number (610763571).

Almost surely, 2^1221527141 is an apocalyptic number.

It is an amenable number.

1221527141 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221527141 is an equidigital number, since it uses as much as digits as its factorization.

1221527141 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1120, while the sum is 26.

The square root of 1221527141 is about 34950.3525161049. The cubic root of 1221527141 is about 1068.9753900298.

Adding to 1221527141 its reverse (1417251221), we get a palindrome (2638778362).

The spelling of 1221527141 in words is "one billion, two hundred twenty-one million, five hundred twenty-seven thousand, one hundred forty-one".