1997029905 has 24 divisors (see below), whose sum is σ = 3459947328. Its totient is φ = 983151936.

The previous prime is 1997029849. The next prime is 1997029949. The reversal of 1997029905 is 5099207991.

It is not a de Polignac number, because 1997029905 - 2⁶ = 1997029841 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 391357 + ... + 396426.

It is an arithmetic number, because the mean of its divisors is an integer number (144164472).

Almost surely, 2^1997029905 is an apocalyptic number.

1997029905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1997029905 is a deficient number, since it is larger than the sum of its proper divisors (1462917423).

1997029905 is a wasteful number, since it uses less digits than its factorization.

1997029905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 787817 (or 787804 counting only the distinct ones).

The product of its (nonzero) digits is 459270, while the sum is 51.

The square root of 1997029905 is about 44688.1405408639. The cubic root of 1997029905 is about 1259.2970600396.

The spelling of 1997029905 in words is "one billion, nine hundred ninety-seven million, twenty-nine thousand, nine hundred five".