20409778 has 16 divisors (see below), whose sum is σ = 31765536. Its totient is φ = 9828000.

The previous prime is 20409773. The next prime is 20409793. The reversal of 20409778 is 87790402.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20409773) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4653 + ... + 7903.

It is an arithmetic number, because the mean of its divisors is an integer number (1985346).

Almost surely, 2^20409778 is an apocalyptic number.

20409778 is a deficient number, since it is larger than the sum of its proper divisors (11355758).

20409778 is a wasteful number, since it uses less digits than its factorization.

20409778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3369.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 20409778 is about 4517.7182293720. The cubic root of 20409778 is about 273.2830904413.

The spelling of 20409778 in words is "twenty million, four hundred nine thousand, seven hundred seventy-eight".