694164409 has 3 divisors (see below), whose sum is σ = 694190757. Its totient is φ = 694138062.

The previous prime is 694164407. The next prime is 694164413. The reversal of 694164409 is 904461496.

The square root of 694164409 is 26347.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 694164409 - 2¹ = 694164407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (694164407) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 13174 + ... + 39520.

It is an arithmetic number, because the mean of its divisors is an integer number (231396919).

Almost surely, 2^694164409 is an apocalyptic number.

694164409 is the 26347-th square number.

694164409 is the 13174-th centered octagonal number.

It is an amenable number.

694164409 is a deficient number, since it is larger than the sum of its proper divisors (26348).

694164409 is an frugal number, since it uses more digits than its factorization.

694164409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52694 (or 26347 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 43.

The cubic root of 694164409 is about 885.4297588227.

Multiplying 694164409 by its product of nonzero digits (186624), we get a square (129547738665216 = 11381904²).

The spelling of 694164409 in words is "six hundred ninety-four million, one hundred sixty-four thousand, four hundred nine".