212040309 has 16 divisors (see below), whose sum is σ = 307488384. Its totient is φ = 129192000.

The previous prime is 212040281. The next prime is 212040313. The reversal of 212040309 is 903040212.

It is not a de Polignac number, because 212040309 - 2⁸ = 212040053 is a prime.

It is a super-2 number, since 2×212040309² = 89922185281630962, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212040329) 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, 22977 + ... + 30854.

It is an arithmetic number, because the mean of its divisors is an integer number (19218024).

Almost surely, 2^212040309 is an apocalyptic number.

It is an amenable number.

212040309 is a deficient number, since it is larger than the sum of its proper divisors (95448075).

212040309 is a wasteful number, since it uses less digits than its factorization.

212040309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53948.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 212040309 is about 14561.6039295127. The cubic root of 212040309 is about 596.3109845371.

The spelling of 212040309 in words is "two hundred twelve million, forty thousand, three hundred nine".