781465897 has 2 divisors, whose sum is σ = 781465898. Its totient is φ = 781465896.

The previous prime is 781465891. The next prime is 781465901. The reversal of 781465897 is 798564187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 778354201 + 3111696 = 27899^2 + 1764^2 .

It is a cyclic number.

It is not a de Polignac number, because 781465897 - 2³ = 781465889 is a prime.

It is a super-2 number, since 2×781465897² = 1221377896348029218, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (781465891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390732948 + 390732949.

It is an arithmetic number, because the mean of its divisors is an integer number (390732949).

Almost surely, 2^781465897 is an apocalyptic number.

It is an amenable number.

781465897 is a deficient number, since it is larger than the sum of its proper divisors (1).

781465897 is an equidigital number, since it uses as much as digits as its factorization.

781465897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3386880, while the sum is 55.

The square root of 781465897 is about 27954.7115349095. The cubic root of 781465897 is about 921.0927064567.

The spelling of 781465897 in words is "seven hundred eighty-one million, four hundred sixty-five thousand, eight hundred ninety-seven".