997720008 has 16 divisors (see below), whose sum is σ = 2494300080. Its totient is φ = 332573328.

The previous prime is 997720007. The next prime is 997720043. The reversal of 997720008 is 800027799.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

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 3 ways as a sum of consecutive naturals, for example, 20785810 + ... + 20785857.

It is an arithmetic number, because the mean of its divisors is an integer number (155893755).

Almost surely, 2^997720008 is an apocalyptic number.

It is an amenable number.

997720008 is an abundant number, since it is smaller than the sum of its proper divisors (1496580072).

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

997720008 is a wasteful number, since it uses less digits than its factorization.

997720008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41571676 (or 41571672 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 42.

The square root of 997720008 is about 31586.7061910545. The cubic root of 997720008 is about 999.2394243380.

The spelling of 997720008 in words is "nine hundred ninety-seven million, seven hundred twenty thousand, eight".