20431778 has 8 divisors (see below), whose sum is σ = 31017168. Its totient is φ = 10092724.

The previous prime is 20431777. The next prime is 20431787. The reversal of 20431778 is 87713402.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (20431777) 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 3 ways as a sum of consecutive naturals, for example, 61376 + ... + 61707.

It is an arithmetic number, because the mean of its divisors is an integer number (3877146).

Almost surely, 2^20431778 is an apocalyptic number.

20431778 is a deficient number, since it is larger than the sum of its proper divisors (10585390).

20431778 is a wasteful number, since it uses less digits than its factorization.

20431778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123168.

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 20431778 is about 4520.1524310581. The cubic root of 20431778 is about 273.3812471362.

The spelling of 20431778 in words is "twenty million, four hundred thirty-one thousand, seven hundred seventy-eight".