1214216021 has 4 divisors (see below), whose sum is σ = 1217695500. Its totient is φ = 1210736544.

The previous prime is 1214215999. The next prime is 1214216039. The reversal of 1214216021 is 1206124121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1206124121 = 1789 ⋅674189.

It can be written as a sum of positive squares in 2 ways, for example, as 320803921 + 893412100 = 17911^2 + 29890^2 .

It is a cyclic number.

It is not a de Polignac number, because 1214216021 - 2¹⁰ = 1214214997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1214215984 and 1214216002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1214210021) 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, 1739216 + ... + 1739913.

It is an arithmetic number, because the mean of its divisors is an integer number (304423875).

Almost surely, 2^1214216021 is an apocalyptic number.

It is an amenable number.

1214216021 is a deficient number, since it is larger than the sum of its proper divisors (3479479).

1214216021 is an equidigital number, since it uses as much as digits as its factorization.

1214216021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3479478.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 1214216021 is about 34845.6026063548. The cubic root of 1214216021 is about 1066.8384333522.

The spelling of 1214216021 in words is "one billion, two hundred fourteen million, two hundred sixteen thousand, twenty-one".