1897667981 has 16 divisors (see below), whose sum is σ = 2086326528. Its totient is φ = 1711756800.

The previous prime is 1897667977. The next prime is 1897668037.

1897667981 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 1897667981 - 2² = 1897667977 is a prime.

It is a super-2 number, since 2×1897667981² = 7202287532225232722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1897667881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 828620 + ... + 830906.

It is an arithmetic number, because the mean of its divisors is an integer number (130395408).

Almost surely, 2^1897667981 is an apocalyptic number.

1897667981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1897667981 is a deficient number, since it is larger than the sum of its proper divisors (188658547).

1897667981 is a wasteful number, since it uses less digits than its factorization.

1897667981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2852.

The product of its digits is 9144576, while the sum is 62.

The square root of 1897667981 is about 43562.2311297298. The cubic root of 1897667981 is about 1238.0553939474.

The spelling of 1897667981 in words is "one billion, eight hundred ninety-seven million, six hundred sixty-seven thousand, nine hundred eighty-one".