1681266291 has 4 divisors (see below), whose sum is σ = 2241688392. Its totient is φ = 1120844192.

The previous prime is 1681266277. The next prime is 1681266317. The reversal of 1681266291 is 1926621861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1926621861 = 3 ⋅642207287.

It is a cyclic number.

It is not a de Polignac number, because 1681266291 - 2¹³ = 1681258099 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1681216291) 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, 280211046 + ... + 280211051.

It is an arithmetic number, because the mean of its divisors is an integer number (560422098).

Almost surely, 2^1681266291 is an apocalyptic number.

1681266291 is a deficient number, since it is larger than the sum of its proper divisors (560422101).

1681266291 is an equidigital number, since it uses as much as digits as its factorization.

1681266291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560422100.

The product of its digits is 62208, while the sum is 42.

The square root of 1681266291 is about 41003.2473226207. The cubic root of 1681266291 is about 1189.0829954965.

The spelling of 1681266291 in words is "one billion, six hundred eighty-one million, two hundred sixty-six thousand, two hundred ninety-one".