997201920 has 384 divisors, whose sum is σ = 3764517120. Its totient is φ = 222167040.

The previous prime is 997201913. The next prime is 997201921. The reversal of 997201920 is 29102799.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997201921) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4392847 + ... + 4393073.

It is an arithmetic number, because the mean of its divisors is an integer number (9803430).

Almost surely, 2^997201920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 997201920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1882258560).

997201920 is an abundant number, since it is smaller than the sum of its proper divisors (2767315200).

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

997201920 is a wasteful number, since it uses less digits than its factorization.

997201920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 261 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 39.

The square root of 997201920 is about 31578.5040810992. The cubic root of 997201920 is about 999.0664353950.

The spelling of 997201920 in words is "nine hundred ninety-seven million, two hundred one thousand, nine hundred twenty".