211010121 has 18 divisors (see below), whose sum is σ = 354555162. Its totient is φ = 120576960.

The previous prime is 211010101. The next prime is 211010123. The reversal of 211010121 is 121010112.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 181198521 + 29811600 = 13461^2 + 5460^2 .

It is not a de Polignac number, because 211010121 - 2⁶ = 211010057 is a prime.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (211010123) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 238800 + ... + 239681.

It is an arithmetic number, because the mean of its divisors is an integer number (19697509).

Almost surely, 2^211010121 is an apocalyptic number.

211010121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

211010121 is a deficient number, since it is larger than the sum of its proper divisors (143545041).

211010121 is a wasteful number, since it uses less digits than its factorization.

211010121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478501 (or 478491 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 211010121 is about 14526.1874213436. The cubic root of 211010121 is about 595.3436999251.

Adding to 211010121 its reverse (121010112), we get a palindrome (332020233).

Subtracting from 211010121 its reverse (121010112), we obtain a palindrome (90000009).

The spelling of 211010121 in words is "two hundred eleven million, ten thousand, one hundred twenty-one".