20778774 has 16 divisors (see below), whose sum is σ = 41610240. Its totient is φ = 6917480.

The previous prime is 20778767. The next prime is 20778781. The reversal of 20778774 is 47787702.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20778767) and next prime (20778781).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 4507 + ... + 7865.

It is an arithmetic number, because the mean of its divisors is an integer number (2600640).

Almost surely, 2^20778774 is an apocalyptic number.

20778774 is an abundant number, since it is smaller than the sum of its proper divisors (20831466).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20778774 is a wasteful number, since it uses less digits than its factorization.

20778774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4395.

The product of its (nonzero) digits is 153664, while the sum is 42.

The square root of 20778774 is about 4558.3740522252. The cubic root of 20778774 is about 274.9201928195.

The spelling of 20778774 in words is "twenty million, seven hundred seventy-eight thousand, seven hundred seventy-four".