1221400457 has 2 divisors, whose sum is σ = 1221400458. Its totient is φ = 1221400456.

The previous prime is 1221400417. The next prime is 1221400463. The reversal of 1221400457 is 7540041221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1043871481 + 177528976 = 32309^2 + 13324^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221400457 - 2¹⁰ = 1221399433 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221400417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610700228 + 610700229.

It is an arithmetic number, because the mean of its divisors is an integer number (610700229).

Almost surely, 2^1221400457 is an apocalyptic number.

It is an amenable number.

1221400457 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221400457 is an equidigital number, since it uses as much as digits as its factorization.

1221400457 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 1221400457 is about 34948.5401268780. The cubic root of 1221400457 is about 1068.9384344422.

Adding to 1221400457 its reverse (7540041221), we get a palindrome (8761441678).

The spelling of 1221400457 in words is "one billion, two hundred twenty-one million, four hundred thousand, four hundred fifty-seven".