20867778 has 24 divisors (see below), whose sum is σ = 46436988. Its totient is φ = 6767712.

The previous prime is 20867773. The next prime is 20867809. The reversal of 20867778 is 87776802.

It can be written as a sum of positive squares in 2 ways, for example, as 14040009 + 6827769 = 3747^2 + 2613^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20867773) 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 11 ways as a sum of consecutive naturals, for example, 15001 + ... + 16332.

Almost surely, 2^20867778 is an apocalyptic number.

20867778 is an abundant number, since it is smaller than the sum of its proper divisors (25569210).

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

20867778 is a wasteful number, since it uses less digits than its factorization.

20867778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31378 (or 31375 counting only the distinct ones).

The product of its (nonzero) digits is 263424, while the sum is 45.

The square root of 20867778 is about 4568.1263117388. The cubic root of 20867778 is about 275.3121656220.

The spelling of 20867778 in words is "twenty million, eight hundred sixty-seven thousand, seven hundred seventy-eight".