20190749 has 4 divisors (see below), whose sum is σ = 21253440. Its totient is φ = 19128060.

The previous prime is 20190743. The next prime is 20190763. The reversal of 20190749 is 94709102.

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, and also an emirpimes, since its reverse is a distinct semiprime: 94709102 = 2 ⋅47354551.

It is not a de Polignac number, because 20190749 - 2⁴ = 20190733 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 (20190743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 531317 + ... + 531354.

It is an arithmetic number, because the mean of its divisors is an integer number (5313360).

Almost surely, 2^20190749 is an apocalyptic number.

It is an amenable number.

20190749 is a deficient number, since it is larger than the sum of its proper divisors (1062691).

20190749 is a wasteful number, since it uses less digits than its factorization.

20190749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1062690.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 20190749 is about 4493.4117327483. The cubic root of 20190749 is about 272.3019867203.

The spelling of 20190749 in words is "twenty million, one hundred ninety thousand, seven hundred forty-nine".