1691323506 has 36 divisors (see below), whose sum is σ = 3881746206. Its totient is φ = 530385600.

The previous prime is 1691323463. The next prime is 1691323507. The reversal of 1691323506 is 6053231961.

1691323506 is a `hidden beast` number, since 16 + 9 + 132 + 3 + 506 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1243620225 + 447703281 = 35265^2 + 21159^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1691323507) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 718231 + ... + 720581.

Almost surely, 2^1691323506 is an apocalyptic number.

1691323506 is an abundant number, since it is smaller than the sum of its proper divisors (2190422700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1691323506 is an equidigital number, since it uses as much as digits as its factorization.

1691323506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4727 (or 2373 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 1691323506 is about 41125.7037143439. The cubic root of 1691323506 is about 1191.4492866357.

The spelling of 1691323506 in words is "one billion, six hundred ninety-one million, three hundred twenty-three thousand, five hundred six".