1691204027 has 2 divisors, whose sum is σ = 1691204028. Its totient is φ = 1691204026.

The previous prime is 1691204023. The next prime is 1691204051. The reversal of 1691204027 is 7204021961.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1691204027 - 2² = 1691204023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1691203984 and 1691204002.

It is not a weakly prime, because it can be changed into another prime (1691204023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845602013 + 845602014.

It is an arithmetic number, because the mean of its divisors is an integer number (845602014).

Almost surely, 2^1691204027 is an apocalyptic number.

1691204027 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691204027 is an equidigital number, since it uses as much as digits as its factorization.

1691204027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 1691204027 is about 41124.2510813267. The cubic root of 1691204027 is about 1191.4212303983.

Adding to 1691204027 its reverse (7204021961), we get a palindrome (8895225988).

The spelling of 1691204027 in words is "one billion, six hundred ninety-one million, two hundred four thousand, twenty-seven".