121621 has 2 divisors, whose sum is σ = 121622. Its totient is φ = 121620.

The previous prime is 121609. The next prime is 121631. The reversal of 121621 is 126121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87025 + 34596 = 295^2 + 186^2 .

It is a cyclic number.

It is not a de Polignac number, because 121621 - 2⁷ = 121493 is a prime.

It is an Ulam number.

121621 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60810 + 60811.

It is an arithmetic number, because the mean of its divisors is an integer number (60811).

2¹²¹⁶²¹ is an apocalyptic number.

It is an amenable number.

121621 is a deficient number, since it is larger than the sum of its proper divisors (1).

121621 is an equidigital number, since it uses as much as digits as its factorization.

121621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24, while the sum is 13.

The square root of 121621 is about 348.7420249984. The cubic root of 121621 is about 49.5453449738.

Adding to 121621 its reverse (126121), we get a palindrome (247742).

The spelling of 121621 in words is "one hundred twenty-one thousand, six hundred twenty-one".