212056721 has 4 divisors (see below), whose sum is σ = 213007872. Its totient is φ = 211105572.

The previous prime is 212056703. The next prime is 212056723. The reversal of 212056721 is 127650212.

212056721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212056721 is a prime.

It is a super-3 number, since 3×212056721³ (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 (212056723) 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, 475241 + ... + 475686.

It is an arithmetic number, because the mean of its divisors is an integer number (53251968).

Almost surely, 2^212056721 is an apocalyptic number.

It is an amenable number.

212056721 is a deficient number, since it is larger than the sum of its proper divisors (951151).

212056721 is an equidigital number, since it uses as much as digits as its factorization.

212056721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951150.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 212056721 is about 14562.1674554305. The cubic root of 212056721 is about 596.3263690386.

The spelling of 212056721 in words is "two hundred twelve million, fifty-six thousand, seven hundred twenty-one".