1213954549 has 2 divisors, whose sum is σ = 1213954550. Its totient is φ = 1213954548.

The previous prime is 1213954541. The next prime is 1213954579. The reversal of 1213954549 is 9454593121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 966899025 + 247055524 = 31095^2 + 15718^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213954549 - 2³ = 1213954541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213954541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606977274 + 606977275.

It is an arithmetic number, because the mean of its divisors is an integer number (606977275).

Almost surely, 2^1213954549 is an apocalyptic number.

It is an amenable number.

1213954549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213954549 is an equidigital number, since it uses as much as digits as its factorization.

1213954549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 194400, while the sum is 43.

The square root of 1213954549 is about 34841.8505392581. The cubic root of 1213954549 is about 1066.7618493947.

The spelling of 1213954549 in words is "one billion, two hundred thirteen million, nine hundred fifty-four thousand, five hundred forty-nine".