1691950859 has 2 divisors, whose sum is σ = 1691950860. Its totient is φ = 1691950858.

The previous prime is 1691950811. The next prime is 1691950867. The reversal of 1691950859 is 9580591961.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1691950859 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1691950859.

It is not a weakly prime, because it can be changed into another prime (1691950879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845975429 + 845975430.

It is an arithmetic number, because the mean of its divisors is an integer number (845975430).

Almost surely, 2^1691950859 is an apocalyptic number.

1691950859 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691950859 is an equidigital number, since it uses as much as digits as its factorization.

1691950859 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 874800, while the sum is 53.

The square root of 1691950859 is about 41133.3302687735. The cubic root of 1691950859 is about 1191.5965809260.

The spelling of 1691950859 in words is "one billion, six hundred ninety-one million, nine hundred fifty thousand, eight hundred fifty-nine".