20121716 has 6 divisors (see below), whose sum is σ = 35213010. Its totient is φ = 10060856.

The previous prime is 20121713. The next prime is 20121719. The reversal of 20121716 is 61712102.

It is an interprime number because it is at equal distance from previous prime (20121713) and next prime (20121719).

It can be written as a sum of positive squares in only one way, i.e., 14409616 + 5712100 = 3796^2 + 2390^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2515211 + ... + 2515218.

It is an arithmetic number, because the mean of its divisors is an integer number (5868835).

Almost surely, 2^20121716 is an apocalyptic number.

It is an amenable number.

20121716 is a deficient number, since it is larger than the sum of its proper divisors (15091294).

20121716 is a wasteful number, since it uses less digits than its factorization.

20121716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5030433 (or 5030431 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 20121716 is about 4485.7235759685. The cubic root of 20121716 is about 271.9912951366.

Adding to 20121716 its reverse (61712102), we get a palindrome (81833818).

The spelling of 20121716 in words is "twenty million, one hundred twenty-one thousand, seven hundred sixteen".