1211991794 has 8 divisors (see below), whose sum is σ = 1957832940. Its totient is φ = 559380816.

The previous prime is 1211991793. The next prime is 1211991799. The reversal of 1211991794 is 4971991121.

It can be written as a sum of positive squares in 2 ways, for example, as 864654025 + 347337769 = 29405^2 + 18637^2 .

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 (1211991793) 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, 23307509 + ... + 23307560.

Almost surely, 2^1211991794 is an apocalyptic number.

1211991794 is a deficient number, since it is larger than the sum of its proper divisors (745841146).

1211991794 is a wasteful number, since it uses less digits than its factorization.

1211991794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46615084.

The product of its digits is 40824, while the sum is 44.

The square root of 1211991794 is about 34813.6725152633. The cubic root of 1211991794 is about 1066.1866159964.

The spelling of 1211991794 in words is "one billion, two hundred eleven million, nine hundred ninety-one thousand, seven hundred ninety-four".