20159997 has 16 divisors (see below), whose sum is σ = 31579968. Its totient is φ = 11278080.

The previous prime is 20159957. The next prime is 20160001. The reversal of 20159997 is 79995102.

It is not a de Polignac number, because 20159997 - 2⁶ = 20159933 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20159917) 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 15 ways as a sum of consecutive naturals, for example, 23068 + ... + 23925.

It is an arithmetic number, because the mean of its divisors is an integer number (1973748).

Almost surely, 2^20159997 is an apocalyptic number.

It is an amenable number.

20159997 is a deficient number, since it is larger than the sum of its proper divisors (11419971).

20159997 is a wasteful number, since it uses less digits than its factorization.

20159997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47020.

The product of its (nonzero) digits is 51030, while the sum is 42.

The square root of 20159997 is about 4489.9885300522. The cubic root of 20159997 is about 272.1636711380.

The spelling of 20159997 in words is "twenty million, one hundred fifty-nine thousand, nine hundred ninety-seven".