20716290 has 128 divisors (see below), whose sum is σ = 64350720. Its totient is φ = 4644864.

The previous prime is 20716279. The next prime is 20716301. The reversal of 20716290 is 9261702.

It is an interprime number because it is at equal distance from previous prime (20716279) and next prime (20716301).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 183274 + ... + 183386.

It is an arithmetic number, because the mean of its divisors is an integer number (502740).

Almost surely, 2^20716290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20716290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32175360).

20716290 is an abundant number, since it is smaller than the sum of its proper divisors (43634430).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20716290 is a wasteful number, since it uses less digits than its factorization.

20716290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 20716290 is about 4551.5151323488. The cubic root of 20716290 is about 274.6443446397.

Adding to 20716290 its reverse (9261702), we get a palindrome (29977992).

The spelling of 20716290 in words is "twenty million, seven hundred sixteen thousand, two hundred ninety".