1321213021 has 8 divisors (see below), whose sum is σ = 1400837760. Its totient is φ = 1241800128.

The previous prime is 1321213009. The next prime is 1321213037. The reversal of 1321213021 is 1203121231.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321213021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1321212986 and 1321213004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321213721) 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, 40021 + ... + 65146.

It is an arithmetic number, because the mean of its divisors is an integer number (175104720).

Almost surely, 2^1321213021 is an apocalyptic number.

It is an amenable number.

1321213021 is a deficient number, since it is larger than the sum of its proper divisors (79624739).

1321213021 is a wasteful number, since it uses less digits than its factorization.

1321213021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105923.

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

The square root of 1321213021 is about 36348.4940678428. The cubic root of 1321213021 is about 1097.2972270812.

Adding to 1321213021 its reverse (1203121231), we get a palindrome (2524334252).

The spelling of 1321213021 in words is "one billion, three hundred twenty-one million, two hundred thirteen thousand, twenty-one".