997720000 has 70 divisors (see below), whose sum is σ = 2474120528. Its totient is φ = 399072000.

The previous prime is 997719991. The next prime is 997720007. The reversal of 997720000 is 27799.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997720007) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 27529 + ... + 52471.

Almost surely, 2^997720000 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 997720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1237060264).

997720000 is an abundant number, since it is smaller than the sum of its proper divisors (1476400528).

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

997720000 is an equidigital number, since it uses as much as digits as its factorization.

997720000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24975 (or 24950 counting only the distinct ones).

The product of its (nonzero) digits is 7938, while the sum is 34.

The square root of 997720000 is about 31586.7060644189. The cubic root of 997720000 is about 999.2394216673.

Adding to 997720000 its reverse (27799), we get a palindrome (997747799).

The spelling of 997720000 in words is "nine hundred ninety-seven million, seven hundred twenty thousand".