1213312021 has 8 divisors (see below), whose sum is σ = 1234508288. Its totient is φ = 1192158000.

The previous prime is 1213312019. The next prime is 1213312033. The reversal of 1213312021 is 1202133121.

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

It is a cyclic number.

It is not a de Polignac number, because 1213312021 - 2¹ = 1213312019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1213311986 and 1213312004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213312081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50416 + ... + 70486.

It is an arithmetic number, because the mean of its divisors is an integer number (154313536).

Almost surely, 2^1213312021 is an apocalyptic number.

It is an amenable number.

1213312021 is a deficient number, since it is larger than the sum of its proper divisors (21196267).

1213312021 is an equidigital number, since it uses as much as digits as its factorization.

1213312021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21123.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1213312021 is about 34832.6286834629. The cubic root of 1213312021 is about 1066.5736091452.

Adding to 1213312021 its reverse (1202133121), we get a palindrome (2415445142).

The spelling of 1213312021 in words is "one billion, two hundred thirteen million, three hundred twelve thousand, twenty-one".