20778315 has 32 divisors (see below), whose sum is σ = 34974720. Its totient is φ = 10513536.

The previous prime is 20778311. The next prime is 20778323. The reversal of 20778315 is 51387702.

It is not a de Polignac number, because 20778315 - 2² = 20778311 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20778311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 78874 + ... + 79136.

It is an arithmetic number, because the mean of its divisors is an integer number (1092960).

Almost surely, 2^20778315 is an apocalyptic number.

20778315 is a deficient number, since it is larger than the sum of its proper divisors (14196405).

20778315 is a wasteful number, since it uses less digits than its factorization.

20778315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523.

The product of its (nonzero) digits is 11760, while the sum is 33.

The square root of 20778315 is about 4558.3237050477. The cubic root of 20778315 is about 274.9181684893.

The spelling of 20778315 in words is "twenty million, seven hundred seventy-eight thousand, three hundred fifteen".