121691519 has 2 divisors, whose sum is σ = 121691520. Its totient is φ = 121691518.

The previous prime is 121691509. The next prime is 121691573. The reversal of 121691519 is 915196121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121691519 - 2²⁰ = 120642943 is a prime.

It is a super-2 number, since 2×121691519² = 29617651593054722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121691509) 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, 60845759 + 60845760.

It is an arithmetic number, because the mean of its divisors is an integer number (60845760).

Almost surely, 2^121691519 is an apocalyptic number.

121691519 is a deficient number, since it is larger than the sum of its proper divisors (1).

121691519 is an equidigital number, since it uses as much as digits as its factorization.

121691519 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4860, while the sum is 35.

The square root of 121691519 is about 11031.3878999879. The cubic root of 121691519 is about 495.5491901422.

The spelling of 121691519 in words is "one hundred twenty-one million, six hundred ninety-one thousand, five hundred nineteen".