1212321021 has 32 divisors (see below), whose sum is σ = 1693605888. Its totient is φ = 770679360.

The previous prime is 1212321013. The next prime is 1212321037. The reversal of 1212321021 is 1201232121.

It is not a de Polignac number, because 1212321021 - 2³ = 1212321013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212321041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1222836 + ... + 1223826.

It is an arithmetic number, because the mean of its divisors is an integer number (52925184).

Almost surely, 2^1212321021 is an apocalyptic number.

It is an amenable number.

1212321021 is a deficient number, since it is larger than the sum of its proper divisors (481284867).

1212321021 is a wasteful number, since it uses less digits than its factorization.

1212321021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1241.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1212321021 is about 34818.4006094479. The cubic root of 1212321021 is about 1066.2831473546.

Adding to 1212321021 its reverse (1201232121), we get a palindrome (2413553142).

Subtracting from 1212321021 its reverse (1201232121), we obtain a square (11088900 = 3330²).

The spelling of 1212321021 in words is "one billion, two hundred twelve million, three hundred twenty-one thousand, twenty-one".