1221253547 has 2 divisors, whose sum is σ = 1221253548. Its totient is φ = 1221253546.

The previous prime is 1221253543. The next prime is 1221253577. The reversal of 1221253547 is 7453521221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221253547 - 2² = 1221253543 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221253543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610626773 + 610626774.

It is an arithmetic number, because the mean of its divisors is an integer number (610626774).

Almost surely, 2^1221253547 is an apocalyptic number.

1221253547 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221253547 is an equidigital number, since it uses as much as digits as its factorization.

1221253547 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16800, while the sum is 32.

The square root of 1221253547 is about 34946.4382591417. The cubic root of 1221253547 is about 1068.8955754325.

Adding to 1221253547 its reverse (7453521221), we get a palindrome (8674774768).

The spelling of 1221253547 in words is "one billion, two hundred twenty-one million, two hundred fifty-three thousand, five hundred forty-seven".