997738990 has 8 divisors (see below), whose sum is σ = 1795930200. Its totient is φ = 399095592.

The previous prime is 997738981. The next prime is 997738991. The reversal of 997738990 is 99837799.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997738991) 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, 49886940 + ... + 49886959.

It is an arithmetic number, because the mean of its divisors is an integer number (224491275).

Almost surely, 2^997738990 is an apocalyptic number.

997738990 is a deficient number, since it is larger than the sum of its proper divisors (798191210).

997738990 is a wasteful number, since it uses less digits than its factorization.

997738990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99773906.

The product of its (nonzero) digits is 7715736, while the sum is 61.

The square root of 997738990 is about 31587.0066641333. The cubic root of 997738990 is about 999.2457612670.

The spelling of 997738990 in words is "nine hundred ninety-seven million, seven hundred thirty-eight thousand, nine hundred ninety".