1138121787 has 8 divisors (see below), whose sum is σ = 1655449920. Its totient is φ = 689770760.

The previous prime is 1138121783. The next prime is 1138121821. The reversal of 1138121787 is 7871218311.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1138121787 - 2² = 1138121783 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1138121783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17244237 + ... + 17244302.

It is an arithmetic number, because the mean of its divisors is an integer number (206931240).

Almost surely, 2^1138121787 is an apocalyptic number.

1138121787 is a deficient number, since it is larger than the sum of its proper divisors (517328133).

1138121787 is a wasteful number, since it uses less digits than its factorization.

1138121787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34488553.

The product of its digits is 18816, while the sum is 39.

The square root of 1138121787 is about 33736.0606325042. The cubic root of 1138121787 is about 1044.0699085980.

The spelling of 1138121787 in words is "one billion, one hundred thirty-eight million, one hundred twenty-one thousand, seven hundred eighty-seven".