1209880921 has 2 divisors, whose sum is σ = 1209880922. Its totient is φ = 1209880920.

The previous prime is 1209880907. The next prime is 1209880999. The reversal of 1209880921 is 1290889021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 659462400 + 550418521 = 25680^2 + 23461^2 .

It is a cyclic number.

It is not a de Polignac number, because 1209880921 - 2⁹ = 1209880409 is a prime.

It is a super-3 number, since 3×1209880921³ (a number of 28 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1209880901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 604940460 + 604940461.

It is an arithmetic number, because the mean of its divisors is an integer number (604940461).

Almost surely, 2^1209880921 is an apocalyptic number.

It is an amenable number.

1209880921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1209880921 is an equidigital number, since it uses as much as digits as its factorization.

1209880921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 1209880921 is about 34783.3425794589. The cubic root of 1209880921 is about 1065.5672794632.

The spelling of 1209880921 in words is "one billion, two hundred nine million, eight hundred eighty thousand, nine hundred twenty-one".