121531919 has 2 divisors, whose sum is σ = 121531920. Its totient is φ = 121531918.

The previous prime is 121531909. The next prime is 121531937. The reversal of 121531919 is 919135121.

It is a weak prime.

It is an emirp because it is prime and its reverse (919135121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121531919 is a prime.

It is a super-2 number, since 2×121531919² = 29540014671645122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121531909) 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 as a sum of consecutive naturals, namely, 60765959 + 60765960.

It is an arithmetic number, because the mean of its divisors is an integer number (60765960).

Almost surely, 2^121531919 is an apocalyptic number.

121531919 is a deficient number, since it is larger than the sum of its proper divisors (1).

121531919 is an equidigital number, since it uses as much as digits as its factorization.

121531919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2430, while the sum is 32.

The square root of 121531919 is about 11024.1516226873. The cubic root of 121531919 is about 495.3324556420.

The spelling of 121531919 in words is "one hundred twenty-one million, five hundred thirty-one thousand, nine hundred nineteen".