20780061 has 4 divisors (see below), whose sum is σ = 27706752. Its totient is φ = 13853372.

The previous prime is 20780059. The next prime is 20780093. The reversal of 20780061 is 16008702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20780061 - 2¹ = 20780059 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20780761) 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, 3463341 + ... + 3463346.

It is an arithmetic number, because the mean of its divisors is an integer number (6926688).

Almost surely, 2^20780061 is an apocalyptic number.

It is an amenable number.

20780061 is a deficient number, since it is larger than the sum of its proper divisors (6926691).

20780061 is an equidigital number, since it uses as much as digits as its factorization.

20780061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6926690.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 20780061 is about 4558.5152187966. The cubic root of 20780061 is about 274.9258687236.

Adding to 20780061 its reverse (16008702), we get a palindrome (36788763).

The spelling of 20780061 in words is "twenty million, seven hundred eighty thousand, sixty-one".