20159749 has 2 divisors, whose sum is σ = 20159750. Its totient is φ = 20159748.

The previous prime is 20159747. The next prime is 20159761. The reversal of 20159749 is 94795102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11009124 + 9150625 = 3318^2 + 3025^2 .

It is a cyclic number.

It is not a de Polignac number, because 20159749 - 2¹ = 20159747 is a prime.

Together with 20159747, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20159747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10079874 + 10079875.

It is an arithmetic number, because the mean of its divisors is an integer number (10079875).

Almost surely, 2^20159749 is an apocalyptic number.

It is an amenable number.

20159749 is a deficient number, since it is larger than the sum of its proper divisors (1).

20159749 is an equidigital number, since it uses as much as digits as its factorization.

20159749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 20159749 is about 4489.9609129702. The cubic root of 20159749 is about 272.1625551182.

The spelling of 20159749 in words is "twenty million, one hundred fifty-nine thousand, seven hundred forty-nine".