20159797 has 4 divisors (see below), whose sum is σ = 23039776. Its totient is φ = 17279820.

The previous prime is 20159771. The next prime is 20159809. The reversal of 20159797 is 79795102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20159797 - 2¹¹ = 20157749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20159747) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1439979 + ... + 1439992.

It is an arithmetic number, because the mean of its divisors is an integer number (5759944).

Almost surely, 2^20159797 is an apocalyptic number.

It is an amenable number.

20159797 is a deficient number, since it is larger than the sum of its proper divisors (2879979).

20159797 is an equidigital number, since it uses as much as digits as its factorization.

20159797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2879978.

The product of its (nonzero) digits is 39690, while the sum is 40.

The square root of 20159797 is about 4489.9662582251. The cubic root of 20159797 is about 272.1627711227.

The spelling of 20159797 in words is "twenty million, one hundred fifty-nine thousand, seven hundred ninety-seven".