121005531 has 6 divisors (see below), whose sum is σ = 174785780. Its totient is φ = 80670348.

The previous prime is 121005529. The next prime is 121005539. The reversal of 121005531 is 135500121.

121005531 is a `hidden beast` number, since 12 + 100 + 553 + 1 = 666.

It is not a de Polignac number, because 121005531 - 2¹ = 121005529 is a prime.

It is a super-2 number, since 2×121005531² = 29284677065183922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121005539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6722521 + ... + 6722538.

Almost surely, 2^121005531 is an apocalyptic number.

121005531 is a deficient number, since it is larger than the sum of its proper divisors (53780249).

121005531 is a wasteful number, since it uses less digits than its factorization.

121005531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13445065 (or 13445062 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 18.

The square root of 121005531 is about 11000.2514062180. The cubic root of 121005531 is about 494.6162805212.

Adding to 121005531 its reverse (135500121), we get a palindrome (256505652).

The spelling of 121005531 in words is "one hundred twenty-one million, five thousand, five hundred thirty-one".