1220209999 has 2 divisors, whose sum is σ = 1220210000. Its totient is φ = 1220209998.

The previous prime is 1220209993. The next prime is 1220210009. The reversal of 1220209999 is 9999020221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1220209999 - 2⁵ = 1220209967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220209993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610104999 + 610105000.

It is an arithmetic number, because the mean of its divisors is an integer number (610105000).

Almost surely, 2^1220209999 is an apocalyptic number.

1220209999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220209999 is an equidigital number, since it uses as much as digits as its factorization.

1220209999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52488, while the sum is 43.

The square root of 1220209999 is about 34931.5043907359. The cubic root of 1220209999 is about 1068.5910354224.

The spelling of 1220209999 in words is "one billion, two hundred twenty million, two hundred nine thousand, nine hundred ninety-nine".