211220001 has 8 divisors (see below), whose sum is σ = 312918560. Its totient is φ = 140813316.

The previous prime is 211219997. The next prime is 211220011. The reversal of 211220001 is 100022112.

211220001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 211220001 - 2² = 211219997 is a prime.

It is a super-2 number, since 2×211220001² = 89227777644880002, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211220011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3911455 + ... + 3911508.

It is an arithmetic number, because the mean of its divisors is an integer number (39114820).

Almost surely, 2^211220001 is an apocalyptic number.

It is an amenable number.

211220001 is a deficient number, since it is larger than the sum of its proper divisors (101698559).

211220001 is an equidigital number, since it uses as much as digits as its factorization.

211220001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7822972 (or 7822966 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 211220001 is about 14533.4098201351. The cubic root of 211220001 is about 595.5410195779.

Adding to 211220001 its reverse (100022112), we get a palindrome (311242113).

The spelling of 211220001 in words is "two hundred eleven million, two hundred twenty thousand, one".