697438409 has 4 divisors (see below), whose sum is σ = 697525140. Its totient is φ = 697351680.

The previous prime is 697438381. The next prime is 697438411. The reversal of 697438409 is 904834796.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 280462009 + 416976400 = 16747^2 + 20420^2 .

It is a cyclic number.

It is not a de Polignac number, because 697438409 - 2²⁴ = 680661193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (697438109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29912 + ... + 47849.

It is an arithmetic number, because the mean of its divisors is an integer number (174381285).

Almost surely, 2^697438409 is an apocalyptic number.

It is an amenable number.

697438409 is a deficient number, since it is larger than the sum of its proper divisors (86731).

697438409 is an equidigital number, since it uses as much as digits as its factorization.

697438409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86730.

The product of its (nonzero) digits is 1306368, while the sum is 50.

The square root of 697438409 is about 26409.0592221684. The cubic root of 697438409 is about 886.8196079635.

The spelling of 697438409 in words is "six hundred ninety-seven million, four hundred thirty-eight thousand, four hundred nine".