212121025 has 24 divisors (see below), whose sum is σ = 268357824. Its totient is φ = 166296000.

The previous prime is 212121023. The next prime is 212121029. The reversal of 212121025 is 520121212.

It is a happy number.

It is not a de Polignac number, because 212121025 - 2¹ = 212121023 is a prime.

It is a super-3 number, since 3×212121025³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212121023) 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 23 ways as a sum of consecutive naturals, for example, 312987 + ... + 313663.

It is an arithmetic number, because the mean of its divisors is an integer number (11181576).

Almost surely, 2^212121025 is an apocalyptic number.

212121025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

212121025 is a deficient number, since it is larger than the sum of its proper divisors (56236799).

212121025 is a wasteful number, since it uses less digits than its factorization.

212121025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921 (or 916 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 212121025 is about 14564.3752011544. The cubic root of 212121025 is about 596.3866395412.

Adding to 212121025 its reverse (520121212), we get a palindrome (732242237).

The spelling of 212121025 in words is "two hundred twelve million, one hundred twenty-one thousand, twenty-five".