121720619 has 2 divisors, whose sum is σ = 121720620. Its totient is φ = 121720618.

The previous prime is 121720609. The next prime is 121720637. The reversal of 121720619 is 916027121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121720619 - 2⁴ = 121720603 is a prime.

It is a super-2 number, since 2×121720619² = 29631818179486322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 121720591 and 121720600.

It is not a weakly prime, because it can be changed into another prime (121720609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60860309 + 60860310.

It is an arithmetic number, because the mean of its divisors is an integer number (60860310).

Almost surely, 2^121720619 is an apocalyptic number.

121720619 is a deficient number, since it is larger than the sum of its proper divisors (1).

121720619 is an equidigital number, since it uses as much as digits as its factorization.

121720619 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 29.

The square root of 121720619 is about 11032.7067848285. The cubic root of 121720619 is about 495.5886870939.

The spelling of 121720619 in words is "one hundred twenty-one million, seven hundred twenty thousand, six hundred nineteen".