20519717 has 4 divisors (see below), whose sum is σ = 20624076. Its totient is φ = 20415360.

The previous prime is 20519713. The next prime is 20519747. The reversal of 20519717 is 71791502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71791502 = 2 ⋅35895751.

It can be written as a sum of positive squares in 2 ways, for example, as 16654561 + 3865156 = 4081^2 + 1966^2 .

It is a cyclic number.

It is not a de Polignac number, because 20519717 - 2² = 20519713 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 (20519713) 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, 51884 + ... + 52277.

It is an arithmetic number, because the mean of its divisors is an integer number (5156019).

Almost surely, 2^20519717 is an apocalyptic number.

It is an amenable number.

20519717 is a deficient number, since it is larger than the sum of its proper divisors (104359).

20519717 is a wasteful number, since it uses less digits than its factorization.

20519717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104358.

The product of its (nonzero) digits is 4410, while the sum is 32.

The square root of 20519717 is about 4529.8694241667. The cubic root of 20519717 is about 273.7728995390.

The spelling of 20519717 in words is "twenty million, five hundred nineteen thousand, seven hundred seventeen".