1249210561 has 2 divisors, whose sum is σ = 1249210562. Its totient is φ = 1249210560.

The previous prime is 1249210553. The next prime is 1249210597. The reversal of 1249210561 is 1650129421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1242985536 + 6225025 = 35256^2 + 2495^2 .

It is a cyclic number.

It is not a de Polignac number, because 1249210561 - 2³ = 1249210553 is a prime.

It is not a weakly prime, because it can be changed into another prime (1249210531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 624605280 + 624605281.

It is an arithmetic number, because the mean of its divisors is an integer number (624605281).

Almost surely, 2^1249210561 is an apocalyptic number.

It is an amenable number.

1249210561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1249210561 is an equidigital number, since it uses as much as digits as its factorization.

1249210561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1249210561 is about 35344.1729426507. The cubic root of 1249210561 is about 1076.9905246240.

Adding to 1249210561 its reverse (1650129421), we get a palindrome (2899339982).

The spelling of 1249210561 in words is "one billion, two hundred forty-nine million, two hundred ten thousand, five hundred sixty-one".