212121007 has 4 divisors (see below), whose sum is σ = 242424016. Its totient is φ = 181818000.

The previous prime is 212120983. The next prime is 212121023. The reversal of 212121007 is 700121212.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-212121007 is a prime.

It is a super-3 number, since 3×212121007³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121067) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15151494 + ... + 15151507.

It is an arithmetic number, because the mean of its divisors is an integer number (60606004).

Almost surely, 2^212121007 is an apocalyptic number.

212121007 is a deficient number, since it is larger than the sum of its proper divisors (30303009).

212121007 is an equidigital number, since it uses as much as digits as its factorization.

212121007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30303008.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 212121007 is about 14564.3745832082. The cubic root of 212121007 is about 596.3866226720.

Adding to 212121007 its reverse (700121212), we get a palindrome (912242219).

The spelling of 212121007 in words is "two hundred twelve million, one hundred twenty-one thousand, seven".