1213987194 has 24 divisors (see below), whose sum is σ = 3006063840. Its totient is φ = 346853448.

The previous prime is 1213987171. The next prime is 1213987199. The reversal of 1213987194 is 4917893121.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1213987199) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4817284 + ... + 4817535.

It is an arithmetic number, because the mean of its divisors is an integer number (125252660).

Almost surely, 2^1213987194 is an apocalyptic number.

1213987194 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

1213987194 is an abundant number, since it is smaller than the sum of its proper divisors (1792076646).

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

1213987194 is a wasteful number, since it uses less digits than its factorization.

1213987194 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9634834 (or 9634831 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 1213987194 is about 34842.3190100774. The cubic root of 1213987194 is about 1066.7714115672.

The spelling of 1213987194 in words is "one billion, two hundred thirteen million, nine hundred eighty-seven thousand, one hundred ninety-four".