919609109621 has 2 divisors, whose sum is σ = 919609109622. Its totient is φ = 919609109620.

The previous prime is 919609109567. The next prime is 919609109701. The reversal of 919609109621 is 126901906919.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 563302786225 + 356306323396 = 750535^2 + 596914^2 .

It is an emirp because it is prime and its reverse (126901906919) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 919609109621 - 2³⁴ = 902429240437 is a prime.

It is a super-3 number, since 3×919609109621³ (a number of 37 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (919609109921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 459804554810 + 459804554811.

It is an arithmetic number, because the mean of its divisors is an integer number (459804554811).

Almost surely, 2^919609109621 is an apocalyptic number.

It is an amenable number.

919609109621 is a deficient number, since it is larger than the sum of its proper divisors (1).

919609109621 is an equidigital number, since it uses as much as digits as its factorization.

919609109621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 472392, while the sum is 53.

The spelling of 919609109621 in words is "nine hundred nineteen billion, six hundred nine million, one hundred nine thousand, six hundred twenty-one".