1691493149 has 8 divisors (see below), whose sum is σ = 1811117880. Its totient is φ = 1574104576.

The previous prime is 1691493143. The next prime is 1691493173. The reversal of 1691493149 is 9413941961.

It can be written as a sum of positive squares in 4 ways, for example, as 166590649 + 1524902500 = 12907^2 + 39050^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1691493149 is a prime.

It is a super-2 number, since 2×1691493149² = 5722298146227872402, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1691493143) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 557474 + ... + 560499.

It is an arithmetic number, because the mean of its divisors is an integer number (226389735).

Almost surely, 2^1691493149 is an apocalyptic number.

It is an amenable number.

1691493149 is a deficient number, since it is larger than the sum of its proper divisors (119624731).

1691493149 is a wasteful number, since it uses less digits than its factorization.

1691493149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118079.

The product of its digits is 209952, while the sum is 47.

The square root of 1691493149 is about 41127.7661562113. The cubic root of 1691493149 is about 1191.4891201888.

The spelling of 1691493149 in words is "one billion, six hundred ninety-one million, four hundred ninety-three thousand, one hundred forty-nine".