1691394143 has 8 divisors (see below), whose sum is σ = 1698224112. Its totient is φ = 1684578816.

The previous prime is 1691394137. The next prime is 1691394151. The reversal of 1691394143 is 3414931961.

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

It is a cyclic number.

It is not a de Polignac number, because 1691394143 - 2¹⁶ = 1691328607 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1691394143.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1691397143) 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, 266321 + ... + 272597.

It is an arithmetic number, because the mean of its divisors is an integer number (212278014).

Almost surely, 2^1691394143 is an apocalyptic number.

1691394143 is a deficient number, since it is larger than the sum of its proper divisors (6829969).

1691394143 is an equidigital number, since it uses as much as digits as its factorization.

1691394143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7321.

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

The square root of 1691394143 is about 41126.5624991927. The cubic root of 1691394143 is about 1191.4658731002.

The spelling of 1691394143 in words is "one billion, six hundred ninety-one million, three hundred ninety-four thousand, one hundred forty-three".