1997866368 has 96 divisors (see below), whose sum is σ = 5889429000. Its totient is φ = 649697280.

The previous prime is 1997866363. The next prime is 1997866379. The reversal of 1997866368 is 8636687991.

1997866368 is a `hidden beast` number, since 199 + 7 + 86 + 6 + 368 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×1997866368² = 7982940048771022848, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1997866363) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26083 + ... + 68381.

Almost surely, 2^1997866368 is an apocalyptic number.

1997866368 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 1997866368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2944714500).

1997866368 is an abundant number, since it is smaller than the sum of its proper divisors (3891562632).

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

1997866368 is a wasteful number, since it uses less digits than its factorization.

1997866368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42360 (or 42345 counting only the distinct ones).

The product of its digits is 23514624, while the sum is 63.

The square root of 1997866368 is about 44697.4984534929. The cubic root of 1997866368 is about 1259.4728558319.

The spelling of 1997866368 in words is "one billion, nine hundred ninety-seven million, eight hundred sixty-six thousand, three hundred sixty-eight".