121531005 has 24 divisors (see below), whose sum is σ = 217451520. Its totient is φ = 62724960.

The previous prime is 121531001. The next prime is 121531019. The reversal of 121531005 is 500135121.

It is not a de Polignac number, because 121531005 - 2² = 121531001 is a prime.

It is a super-3 number, since 3×121531005³ (a number of 25 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121531001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 42165 + ... + 44954.

It is an arithmetic number, because the mean of its divisors is an integer number (9060480).

Almost surely, 2^121531005 is an apocalyptic number.

121531005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121531005 is a deficient number, since it is larger than the sum of its proper divisors (95920515).

121531005 is a wasteful number, since it uses less digits than its factorization.

121531005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87161 (or 87158 counting only the distinct ones).

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

The square root of 121531005 is about 11024.1101681723. The cubic root of 121531005 is about 495.3312138969.

Adding to 121531005 its reverse (500135121), we get a palindrome (621666126).

The spelling of 121531005 in words is "one hundred twenty-one million, five hundred thirty-one thousand, five".