1209981138 has 16 divisors (see below), whose sum is σ = 2449119456. Its totient is φ = 398467520.

The previous prime is 1209981121. The next prime is 1209981163. The reversal of 1209981138 is 8311899021.

It is a self number, because there is not a number n which added to its sum of digits gives 1209981138.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1214343 + ... + 1215338.

It is an arithmetic number, because the mean of its divisors is an integer number (153069966).

Almost surely, 2^1209981138 is an apocalyptic number.

1209981138 is an abundant number, since it is smaller than the sum of its proper divisors (1239138318).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1209981138 is a wasteful number, since it uses less digits than its factorization.

1209981138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2429769.

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 1209981138 is about 34784.7831386082. The cubic root of 1209981138 is about 1065.5966997160.

The spelling of 1209981138 in words is "one billion, two hundred nine million, nine hundred eighty-one thousand, one hundred thirty-eight".