20778754 has 4 divisors (see below), whose sum is σ = 31168134. Its totient is φ = 10389376.

The previous prime is 20778749. The next prime is 20778757. The reversal of 20778754 is 45787702.

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., 18447025 + 2331729 = 4295^2 + 1527^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (20778757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5194687 + ... + 5194690.

Almost surely, 2^20778754 is an apocalyptic number.

20778754 is a deficient number, since it is larger than the sum of its proper divisors (10389380).

20778754 is a wasteful number, since it uses less digits than its factorization.

20778754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10389379.

The product of its (nonzero) digits is 109760, while the sum is 40.

The square root of 20778754 is about 4558.3718584600. The cubic root of 20778754 is about 274.9201046140.

It can be divided in two parts, 207 and 78754, that added together give a square (78961 = 281²).

The spelling of 20778754 in words is "twenty million, seven hundred seventy-eight thousand, seven hundred fifty-four".