20780071 has 12 divisors (see below), whose sum is σ = 23058000. Its totient is φ = 18707520.

The previous prime is 20780059. The next prime is 20780093. The reversal of 20780071 is 17008702.

It is a happy number.

It is not a de Polignac number, because 20780071 - 2¹⁵ = 20747303 is a prime.

It is a super-2 number, since 2×20780071² = 863622701530082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20781071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5430 + ... + 8428.

It is an arithmetic number, because the mean of its divisors is an integer number (1921500).

Almost surely, 2^20780071 is an apocalyptic number.

20780071 is a deficient number, since it is larger than the sum of its proper divisors (2277929).

20780071 is a wasteful number, since it uses less digits than its factorization.

20780071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3066 (or 3053 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 25.

The square root of 20780071 is about 4558.5163156448. The cubic root of 20780071 is about 274.9259128245.

Adding to 20780071 its reverse (17008702), we get a palindrome (37788773).

The spelling of 20780071 in words is "twenty million, seven hundred eighty thousand, seventy-one".