121540421 has 4 divisors (see below), whose sum is σ = 125731500. Its totient is φ = 117349344.

The previous prime is 121540409. The next prime is 121540423. The reversal of 121540421 is 124045121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 32615521 + 88924900 = 5711^2 + 9430^2 .

It is a cyclic number.

It is not a de Polignac number, because 121540421 - 2⁶ = 121540357 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121540393 and 121540402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121540423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2095496 + ... + 2095553.

It is an arithmetic number, because the mean of its divisors is an integer number (31432875).

Almost surely, 2^121540421 is an apocalyptic number.

It is an amenable number.

121540421 is a deficient number, since it is larger than the sum of its proper divisors (4191079).

121540421 is an equidigital number, since it uses as much as digits as its factorization.

121540421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4191078.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 121540421 is about 11024.5372238475. The cubic root of 121540421 is about 495.3440060187.

Adding to 121540421 its reverse (124045121), we get a palindrome (245585542).

The spelling of 121540421 in words is "one hundred twenty-one million, five hundred forty thousand, four hundred twenty-one".