1213000020 has 36 divisors (see below), whose sum is σ = 3679433940. Its totient is φ = 323466624.

The previous prime is 1213000003. The next prime is 1213000021. The reversal of 1213000020 is 200003121.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 262634436 + 950365584 = 16206^2 + 30828^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 1212999966 and 1213000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213000021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3369265 + ... + 3369624.

Almost surely, 2^1213000020 is an apocalyptic number.

1213000020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1213000020 is an abundant number, since it is smaller than the sum of its proper divisors (2466433920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1213000020 is a wasteful number, since it uses less digits than its factorization.

1213000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6738904 (or 6738899 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 1213000020 is about 34828.1498216601. The cubic root of 1213000020 is about 1066.4821788138.

Adding to 1213000020 its reverse (200003121), we get a palindrome (1413003141).

The spelling of 1213000020 in words is "one billion, two hundred thirteen million, twenty", and thus it is an aban number.