1211890138 has 8 divisors (see below), whose sum is σ = 1839737088. Its totient is φ = 598644444.

The previous prime is 1211890133. The next prime is 1211890181. The reversal of 1211890138 is 8310981121.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (1211890133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3650106 + ... + 3650437.

It is an arithmetic number, because the mean of its divisors is an integer number (229967136).

Almost surely, 2^1211890138 is an apocalyptic number.

1211890138 is a deficient number, since it is larger than the sum of its proper divisors (627846950).

1211890138 is an equidigital number, since it uses as much as digits as its factorization.

1211890138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7300628.

The product of its (nonzero) digits is 3456, while the sum is 34.

The square root of 1211890138 is about 34812.2124835524. The cubic root of 1211890138 is about 1066.1568063069.

The spelling of 1211890138 in words is "one billion, two hundred eleven million, eight hundred ninety thousand, one hundred thirty-eight".