1219891049 has 32 divisors (see below), whose sum is σ = 1422036000. Its totient is φ = 1036468224.

The previous prime is 1219891033. The next prime is 1219891051. The reversal of 1219891049 is 9401989121.

It can be written as a sum of positive squares in 16 ways, for example, as 492618025 + 727273024 = 22195^2 + 26968^2 .

It is a cyclic number.

It is not a de Polignac number, because 1219891049 - 2⁴ = 1219891033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1219891019) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2143637 + ... + 2144205.

It is an arithmetic number, because the mean of its divisors is an integer number (44438625).

Almost surely, 2^1219891049 is an apocalyptic number.

It is an amenable number.

1219891049 is a deficient number, since it is larger than the sum of its proper divisors (202144951).

1219891049 is a wasteful number, since it uses less digits than its factorization.

1219891049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797.

The product of its (nonzero) digits is 46656, while the sum is 44.

The square root of 1219891049 is about 34926.9387292960. The cubic root of 1219891049 is about 1068.4979211739.

The spelling of 1219891049 in words is "one billion, two hundred nineteen million, eight hundred ninety-one thousand, forty-nine".