1997729565 has 48 divisors (see below), whose sum is σ = 3518167680. Its totient is φ = 967299840.

The previous prime is 1997729549. The next prime is 1997729579. The reversal of 1997729565 is 5659277991.

It is not a de Polignac number, because 1997729565 - 2⁴ = 1997729549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1997729499 and 1997729508.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 148176 + ... + 161094.

It is an arithmetic number, because the mean of its divisors is an integer number (73295160).

Almost surely, 2^1997729565 is an apocalyptic number.

1997729565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1997729565 is a deficient number, since it is larger than the sum of its proper divisors (1520438115).

1997729565 is a wasteful number, since it uses less digits than its factorization.

1997729565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13014 (or 13001 counting only the distinct ones).

The product of its digits is 10716300, while the sum is 60.

The square root of 1997729565 is about 44695.9681067543. The cubic root of 1997729565 is about 1259.4441078969. Note that the first 3 decimals are identical.

The spelling of 1997729565 in words is "one billion, nine hundred ninety-seven million, seven hundred twenty-nine thousand, five hundred sixty-five".