121721453 has 16 divisors (see below), whose sum is σ = 144168960. Its totient is φ = 100590336.

The previous prime is 121721449. The next prime is 121721459. The reversal of 121721453 is 354127121.

It is not a de Polignac number, because 121721453 - 2² = 121721449 is a prime.

It is a super-2 number, since 2×121721453² = 29632224240862418, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121721459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27188 + ... + 31346.

It is an arithmetic number, because the mean of its divisors is an integer number (9010560).

Almost surely, 2^121721453 is an apocalyptic number.

It is an amenable number.

121721453 is a deficient number, since it is larger than the sum of its proper divisors (22447507).

121721453 is a wasteful number, since it uses less digits than its factorization.

121721453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4316.

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

The square root of 121721453 is about 11032.7445814720. The cubic root of 121721453 is about 495.5898189756.

Adding to 121721453 its reverse (354127121), we get a palindrome (475848574).

The spelling of 121721453 in words is "one hundred twenty-one million, seven hundred twenty-one thousand, four hundred fifty-three".