1897447981 has 8 divisors (see below), whose sum is σ = 2229169824. Its totient is φ = 1592263920.

The previous prime is 1897447967. The next prime is 1897448029.

1897447981 is nontrivially palindromic in base 10.

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

It is not a de Polignac number, because 1897447981 - 2¹¹ = 1897445933 is a prime.

It is a super-2 number, since 2×1897447981² = 7200617681201952722, 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 (1897447921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6634291 + ... + 6634576.

It is an arithmetic number, because the mean of its divisors is an integer number (278646228).

Almost surely, 2^1897447981 is an apocalyptic number.

1897447981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1897447981 is a deficient number, since it is larger than the sum of its proper divisors (331721843).

1897447981 is a wasteful number, since it uses less digits than its factorization.

1897447981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13268891.

The product of its digits is 4064256, while the sum is 58.

The square root of 1897447981 is about 43559.7059333508. The cubic root of 1897447981 is about 1238.0075487824.

The spelling of 1897447981 in words is "one billion, eight hundred ninety-seven million, four hundred forty-seven thousand, nine hundred eighty-one".