121531261 has 4 divisors (see below), whose sum is σ = 122040000. Its totient is φ = 121022524.

The previous prime is 121531259. The next prime is 121531271. The reversal of 121531261 is 162135121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121531261 - 2¹ = 121531259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121531211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254011 + ... + 254488.

It is an arithmetic number, because the mean of its divisors is an integer number (30510000).

Almost surely, 2^121531261 is an apocalyptic number.

It is an amenable number.

121531261 is a deficient number, since it is larger than the sum of its proper divisors (508739).

121531261 is an equidigital number, since it uses as much as digits as its factorization.

121531261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508738.

The product of its digits is 360, while the sum is 22.

The square root of 121531261 is about 11024.1217790806. The cubic root of 121531261 is about 495.3315616948.

Adding to 121531261 its reverse (162135121), we get a palindrome (283666382).

The spelling of 121531261 in words is "one hundred twenty-one million, five hundred thirty-one thousand, two hundred sixty-one".