1212172520 has 64 divisors (see below), whose sum is σ = 2952346320. Its totient is φ = 445261824.

The previous prime is 1212172501. The next prime is 1212172529. The reversal of 1212172520 is 252712121.

It can be written as a sum of positive squares in 8 ways, for example, as 975812644 + 236359876 = 31238^2 + 15374^2 .

It is not an unprimeable number, because it can be changed into a prime (1212172529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 96524 + ... + 108356.

Almost surely, 2^1212172520 is an apocalyptic number.

1212172520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1212172520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1476173160).

1212172520 is an abundant number, since it is smaller than the sum of its proper divisors (1740173800).

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

1212172520 is a wasteful number, since it uses less digits than its factorization.

1212172520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12054 (or 12050 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 1212172520 is about 34816.2680366521. The cubic root of 1212172520 is about 1066.2396081224.

Adding to 1212172520 its reverse (252712121), we get a palindrome (1464884641).

The spelling of 1212172520 in words is "one billion, two hundred twelve million, one hundred seventy-two thousand, five hundred twenty".