197891568 has 120 divisors (see below), whose sum is σ = 638003808. Its totient is φ = 56088576.

The previous prime is 197891567. The next prime is 197891579. The reversal of 197891568 is 865198791.

197891568 is a `hidden beast` number, since 1 + 9 + 78 + 9 + 1 + 568 = 666.

It is a super-2 number, since 2×197891568² = 78322145370997248, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197891567) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 137380 + ... + 138812.

Almost surely, 2^197891568 is an apocalyptic number.

197891568 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 197891568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319001904).

197891568 is an abundant number, since it is smaller than the sum of its proper divisors (440112240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

197891568 is a wasteful number, since it uses less digits than its factorization.

197891568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1591 (or 1582 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 54.

The square root of 197891568 is about 14067.3937884741. The cubic root of 197891568 is about 582.7412527045.

The spelling of 197891568 in words is "one hundred ninety-seven million, eight hundred ninety-one thousand, five hundred sixty-eight".