1623916331909 has 2 divisors, whose sum is σ = 1623916331910. Its totient is φ = 1623916331908.

The previous prime is 1623916331879. The next prime is 1623916331927. The reversal of 1623916331909 is 9091336193261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1568262803809 + 55653528100 = 1252303^2 + 235910^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1623916331909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1623916331959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 811958165954 + 811958165955.

It is an arithmetic number, because the mean of its divisors is an integer number (811958165955).

Almost surely, 2^{1623916331909} is an apocalyptic number.

It is an amenable number.

1623916331909 is a deficient number, since it is larger than the sum of its proper divisors (1).

1623916331909 is an equidigital number, since it uses as much as digits as its factorization.

1623916331909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1417176, while the sum is 53.

The spelling of 1623916331909 in words is "one trillion, six hundred twenty-three billion, nine hundred sixteen million, three hundred thirty-one thousand, nine hundred nine".