1915890997 has 2 divisors, whose sum is σ = 1915890998. Its totient is φ = 1915890996.

The previous prime is 1915890979. The next prime is 1915891057. The reversal of 1915890997 is 7990985191.

It is a happy number.

Together with previous prime (1915890979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1824229521 + 91661476 = 42711^2 + 9574^2 .

It is a cyclic number.

It is not a de Polignac number, because 1915890997 - 2¹⁹ = 1915366709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1915890937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 957945498 + 957945499.

It is an arithmetic number, because the mean of its divisors is an integer number (957945499).

Almost surely, 2^1915890997 is an apocalyptic number.

It is an amenable number.

1915890997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1915890997 is an equidigital number, since it uses as much as digits as its factorization.

1915890997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1837080, while the sum is 58.

The square root of 1915890997 is about 43770.8921202207. The cubic root of 1915890997 is about 1242.0057283151.

The spelling of 1915890997 in words is "one billion, nine hundred fifteen million, eight hundred ninety thousand, nine hundred ninety-seven".