121420785621 has 4 divisors (see below), whose sum is σ = 161894380832. Its totient is φ = 80947190412.

The previous prime is 121420785617. The next prime is 121420785653. The reversal of 121420785621 is 126587024121.

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 not a de Polignac number, because 121420785621 - 2² = 121420785617 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121420785621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121420785121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20236797601 + ... + 20236797606.

It is an arithmetic number, because the mean of its divisors is an integer number (40473595208).

Almost surely, 2^121420785621 is an apocalyptic number.

It is an amenable number.

121420785621 is a deficient number, since it is larger than the sum of its proper divisors (40473595211).

121420785621 is an equidigital number, since it uses as much as digits as its factorization.

121420785621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40473595210.

The product of its (nonzero) digits is 53760, while the sum is 39.

The spelling of 121420785621 in words is "one hundred twenty-one billion, four hundred twenty million, seven hundred eighty-five thousand, six hundred twenty-one".