20780109 has 24 divisors (see below), whose sum is σ = 35797632. Its totient is φ = 11357280.

The previous prime is 20780093. The next prime is 20780113. The reversal of 20780109 is 90108702.

It is not a de Polignac number, because 20780109 - 2⁴ = 20780093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20780119) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5722 + ... + 8619.

It is an arithmetic number, because the mean of its divisors is an integer number (1491568).

Almost surely, 2^20780109 is an apocalyptic number.

It is an amenable number.

20780109 is a deficient number, since it is larger than the sum of its proper divisors (15017523).

20780109 is a wasteful number, since it uses less digits than its factorization.

20780109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14377 (or 14374 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 20780109 is about 4558.5204836657. The cubic root of 20780109 is about 274.9260804078.

The spelling of 20780109 in words is "twenty million, seven hundred eighty thousand, one hundred nine".