1210213021 has 4 divisors (see below), whose sum is σ = 1210333212. Its totient is φ = 1210092832.

The previous prime is 1210213009. The next prime is 1210213063. The reversal of 1210213021 is 1203120121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1203120121 = 7 ⋅171874303.

It can be written as a sum of positive squares in 2 ways, for example, as 784616121 + 425596900 = 28011^2 + 20630^2 .

It is a cyclic number.

It is not a de Polignac number, because 1210213021 - 2⁵ = 1210212989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1210212992 and 1210213010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210213321) 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, 43456 + ... + 65641.

It is an arithmetic number, because the mean of its divisors is an integer number (302583303).

Almost surely, 2^1210213021 is an apocalyptic number.

It is an amenable number.

1210213021 is a deficient number, since it is larger than the sum of its proper divisors (120191).

1210213021 is a wasteful number, since it uses less digits than its factorization.

1210213021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120190.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1210213021 is about 34788.1160886875. The cubic root of 1210213021 is about 1065.6647663353.

Adding to 1210213021 its reverse (1203120121), we get a palindrome (2413333142).

The spelling of 1210213021 in words is "one billion, two hundred ten million, two hundred thirteen thousand, twenty-one".