1243287899 has 16 divisors (see below), whose sum is σ = 1436202240. Its totient is φ = 1054231200.

The previous prime is 1243287889. The next prime is 1243287901. The reversal of 1243287899 is 9987823421.

It is a cyclic number.

It is not a de Polignac number, because 1243287899 - 2¹² = 1243283803 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1243287899.

It is not an unprimeable number, because it can be changed into a prime (1243287869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 856124 + ... + 857574.

It is an arithmetic number, because the mean of its divisors is an integer number (89762640).

Almost surely, 2^1243287899 is an apocalyptic number.

1243287899 is a deficient number, since it is larger than the sum of its proper divisors (192914341).

1243287899 is a wasteful number, since it uses less digits than its factorization.

1243287899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2690.

The product of its digits is 1741824, while the sum is 53.

The square root of 1243287899 is about 35260.2878462443. The cubic root of 1243287899 is about 1075.2857791503.

The spelling of 1243287899 in words is "one billion, two hundred forty-three million, two hundred eighty-seven thousand, eight hundred ninety-nine".