997723990 has 16 divisors (see below), whose sum is σ = 1834114752. Its totient is φ = 390598144.

The previous prime is 997723973. The next prime is 997723997. The reversal of 997723990 is 99327799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997723997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1060939 + ... + 1061878.

It is an arithmetic number, because the mean of its divisors is an integer number (114632172).

Almost surely, 2^997723990 is an apocalyptic number.

997723990 is a deficient number, since it is larger than the sum of its proper divisors (836390762).

997723990 is a wasteful number, since it uses less digits than its factorization.

997723990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2122871.

The product of its (nonzero) digits is 1928934, while the sum is 55.

The square root of 997723990 is about 31586.7692238380. The cubic root of 997723990 is about 999.2407536909.

The spelling of 997723990 in words is "nine hundred ninety-seven million, seven hundred twenty-three thousand, nine hundred ninety".