121719821 has 4 divisors (see below), whose sum is σ = 122400000. Its totient is φ = 121039644.

The previous prime is 121719791. The next prime is 121719823. The reversal of 121719821 is 128917121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121719821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121719823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 339821 + ... + 340178.

It is an arithmetic number, because the mean of its divisors is an integer number (30600000).

Almost surely, 2^121719821 is an apocalyptic number.

It is an amenable number.

121719821 is a deficient number, since it is larger than the sum of its proper divisors (680179).

121719821 is an equidigital number, since it uses as much as digits as its factorization.

121719821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 680178.

The product of its digits is 2016, while the sum is 32.

The square root of 121719821 is about 11032.6706195735. The cubic root of 121719821 is about 495.5876040656.

The spelling of 121719821 in words is "one hundred twenty-one million, seven hundred nineteen thousand, eight hundred twenty-one".