1212531021 has 12 divisors (see below), whose sum is σ = 1886159548. Its totient is φ = 746172864.

The previous prime is 1212531011. The next prime is 1212531029. The reversal of 1212531021 is 1201352121.

It can be written as a sum of positive squares in 2 ways, for example, as 96236100 + 1116294921 = 9810^2 + 33411^2 .

It is not a de Polignac number, because 1212531021 - 2⁵ = 1212530989 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1212530985 and 1212531003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212531029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5181640 + ... + 5181873.

Almost surely, 2^1212531021 is an apocalyptic number.

It is an amenable number.

1212531021 is a deficient number, since it is larger than the sum of its proper divisors (673628527).

1212531021 is a wasteful number, since it uses less digits than its factorization.

1212531021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10363532 (or 10363529 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 1212531021 is about 34821.4161257121. The cubic root of 1212531021 is about 1066.3447115028.

Adding to 1212531021 its reverse (1201352121), we get a palindrome (2413883142).

The spelling of 1212531021 in words is "one billion, two hundred twelve million, five hundred thirty-one thousand, twenty-one".