20780407 has 8 divisors (see below), whose sum is σ = 21096656. Its totient is φ = 20466432.

The previous prime is 20780393. The next prime is 20780411. The reversal of 20780407 is 70408702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20780407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20780807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27073 + ... + 27829.

It is an arithmetic number, because the mean of its divisors is an integer number (2637082).

Almost surely, 2^20780407 is an apocalyptic number.

20780407 is a deficient number, since it is larger than the sum of its proper divisors (316249).

20780407 is an equidigital number, since it uses as much as digits as its factorization.

20780407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1137.

The product of its (nonzero) digits is 3136, while the sum is 28.

The square root of 20780407 is about 4558.5531695923. The cubic root of 20780407 is about 274.9273946065.

The spelling of 20780407 in words is "twenty million, seven hundred eighty thousand, four hundred seven".