1213920971 has 4 divisors (see below), whose sum is σ = 1253079744. Its totient is φ = 1174762200.

The previous prime is 1213920959. The next prime is 1213921019. The reversal of 1213920971 is 1790293121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1213920971 - 2²² = 1209726667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213920571) 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 3 ways as a sum of consecutive naturals, for example, 19579340 + ... + 19579401.

It is an arithmetic number, because the mean of its divisors is an integer number (313269936).

Almost surely, 2^1213920971 is an apocalyptic number.

1213920971 is a deficient number, since it is larger than the sum of its proper divisors (39158773).

1213920971 is an equidigital number, since it uses as much as digits as its factorization.

1213920971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39158772.

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 1213920971 is about 34841.3686728865. The cubic root of 1213920971 is about 1066.7520137547.

The spelling of 1213920971 in words is "one billion, two hundred thirteen million, nine hundred twenty thousand, nine hundred seventy-one".