121211001 has 24 divisors (see below), whose sum is σ = 180685440. Its totient is φ = 78242976.

The previous prime is 121210951. The next prime is 121211017. The reversal of 121211001 is 100112121.

It is a happy number.

It is not a de Polignac number, because 121211001 - 2⁹ = 121210489 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (121211021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78826 + ... + 80348.

It is an arithmetic number, because the mean of its divisors is an integer number (7528560).

Almost surely, 2^121211001 is an apocalyptic number.

It is an amenable number.

121211001 is a deficient number, since it is larger than the sum of its proper divisors (59474439).

121211001 is a wasteful number, since it uses less digits than its factorization.

121211001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1805 (or 1802 counting only the distinct ones).

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

The square root of 121211001 is about 11009.5867769867. The cubic root of 121211001 is about 494.8960785819.

Adding to 121211001 its reverse (100112121), we get a palindrome (221323122).

It can be divided in two parts, 12121 and 1001, that multiplied together give a palindrome (12133121).

The spelling of 121211001 in words is "one hundred twenty-one million, two hundred eleven thousand, one".