1221404057 has 2 divisors, whose sum is σ = 1221404058. Its totient is φ = 1221404056.

The previous prime is 1221404033. The next prime is 1221404059. The reversal of 1221404057 is 7504041221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1185356041 + 36048016 = 34429^2 + 6004^2 .

It is an emirp because it is prime and its reverse (7504041221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221404057 - 2¹⁰ = 1221403033 is a prime.

Together with 1221404059, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1221404059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610702028 + 610702029.

It is an arithmetic number, because the mean of its divisors is an integer number (610702029).

Almost surely, 2^1221404057 is an apocalyptic number.

It is an amenable number.

1221404057 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221404057 is an equidigital number, since it uses as much as digits as its factorization.

1221404057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 1221404057 is about 34948.5916311373. The cubic root of 1221404057 is about 1068.9394846504.

Adding to 1221404057 its reverse (7504041221), we get a palindrome (8725445278).

The spelling of 1221404057 in words is "one billion, two hundred twenty-one million, four hundred four thousand, fifty-seven".