20778722 has 4 divisors (see below), whose sum is σ = 31168086. Its totient is φ = 10389360.

The previous prime is 20778721. The next prime is 20778731. The reversal of 20778722 is 22787702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 14523721 + 6255001 = 3811^2 + 2501^2 .

It is not an unprimeable number, because it can be changed into a prime (20778721) 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 as a sum of consecutive naturals, namely, 5194679 + ... + 5194682.

Almost surely, 2^20778722 is an apocalyptic number.

20778722 is a deficient number, since it is larger than the sum of its proper divisors (10389364).

20778722 is a wasteful number, since it uses less digits than its factorization.

20778722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10389363.

The product of its (nonzero) digits is 21952, while the sum is 35.

The square root of 20778722 is about 4558.3683484335. The cubic root of 20778722 is about 274.9199634851.

The spelling of 20778722 in words is "twenty million, seven hundred seventy-eight thousand, seven hundred twenty-two".