1691394413 has 4 divisors (see below), whose sum is σ = 1790888220. Its totient is φ = 1591900608.

The previous prime is 1691394407. The next prime is 1691394433. The reversal of 1691394413 is 3144931961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3144931961 = 67 ⋅46939283.

It can be written as a sum of positive squares in 2 ways, for example, as 973315204 + 718079209 = 31198^2 + 26797^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1691394413 is a prime.

It is a super-2 number, since 2×1691394413² = 5721630120655229138, 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 (1691394433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49746878 + ... + 49746911.

It is an arithmetic number, because the mean of its divisors is an integer number (447722055).

Almost surely, 2^1691394413 is an apocalyptic number.

It is an amenable number.

1691394413 is a deficient number, since it is larger than the sum of its proper divisors (99493807).

1691394413 is an equidigital number, since it uses as much as digits as its factorization.

1691394413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99493806.

The product of its digits is 69984, while the sum is 41.

The square root of 1691394413 is about 41126.5657817426. The cubic root of 1691394413 is about 1191.4659364987.

The spelling of 1691394413 in words is "one billion, six hundred ninety-one million, three hundred ninety-four thousand, four hundred thirteen".