121721443 has 8 divisors (see below), whose sum is σ = 124203456. Its totient is φ = 119246400.

The previous prime is 121721437. The next prime is 121721447. The reversal of 121721443 is 344127121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121721443 is a prime.

It is a super-2 number, since 2×121721443² = 29632219372004498, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121721447) 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, 47023 + ... + 49543.

It is an arithmetic number, because the mean of its divisors is an integer number (15525432).

Almost surely, 2^121721443 is an apocalyptic number.

121721443 is a deficient number, since it is larger than the sum of its proper divisors (2482013).

121721443 is an equidigital number, since it uses as much as digits as its factorization.

121721443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3485.

The product of its digits is 1344, while the sum is 25.

The square root of 121721443 is about 11032.7441282756. The cubic root of 121721443 is about 495.5898054039.

Adding to 121721443 its reverse (344127121), we get a palindrome (465848564).

The spelling of 121721443 in words is "one hundred twenty-one million, seven hundred twenty-one thousand, four hundred forty-three".