121217145 has 16 divisors (see below), whose sum is σ = 221654400. Its totient is φ = 55413504.

The previous prime is 121217141. The next prime is 121217147. The reversal of 121217145 is 541712121.

It is not a de Polignac number, because 121217145 - 2² = 121217141 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121217141) 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, 577120 + ... + 577329.

It is an arithmetic number, because the mean of its divisors is an integer number (13853400).

Almost surely, 2^121217145 is an apocalyptic number.

121217145 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121217145 is a deficient number, since it is larger than the sum of its proper divisors (100437255).

121217145 is a wasteful number, since it uses less digits than its factorization.

121217145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1154464.

The product of its digits is 560, while the sum is 24.

The square root of 121217145 is about 11009.8658029969. The cubic root of 121217145 is about 494.9044402821.

Adding to 121217145 its reverse (541712121), we get a palindrome (662929266).

The spelling of 121217145 in words is "one hundred twenty-one million, two hundred seventeen thousand, one hundred forty-five".