19820997 has 64 divisors (see below), whose sum is σ = 36864000. Its totient is φ = 10264320.

The previous prime is 19820989. The next prime is 19821013. The reversal of 19820997 is 79902891.

It is not a de Polignac number, because 19820997 - 2³ = 19820989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19820497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 99504 + ... + 99702.

It is an arithmetic number, because the mean of its divisors is an integer number (576000).

Almost surely, 2^19820997 is an apocalyptic number.

19820997 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

19820997 is a deficient number, since it is larger than the sum of its proper divisors (17043003).

19820997 is a wasteful number, since it uses less digits than its factorization.

19820997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263 (or 257 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 19820997 is about 4452.0778295084. The cubic root of 19820997 is about 270.6295187585.

The spelling of 19820997 in words is "nineteen million, eight hundred twenty thousand, nine hundred ninety-seven".