1919591934521 has 2 divisors, whose sum is σ = 1919591934522. Its totient is φ = 1919591934520.

The previous prime is 1919591934509. The next prime is 1919591934587. The reversal of 1919591934521 is 1254391959191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1166376240121 + 753215694400 = 1079989^2 + 867880^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1919591934521 is a prime.

It is not a weakly prime, because it can be changed into another prime (1919591933521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959795967260 + 959795967261.

It is an arithmetic number, because the mean of its divisors is an integer number (959795967261).

Almost surely, 2^{1919591934521} is an apocalyptic number.

It is an amenable number.

1919591934521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919591934521 is an equidigital number, since it uses as much as digits as its factorization.

1919591934521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3936600, while the sum is 59.

The spelling of 1919591934521 in words is "one trillion, nine hundred nineteen billion, five hundred ninety-one million, nine hundred thirty-four thousand, five hundred twenty-one".