20400404 has 24 divisors (see below), whose sum is σ = 36996960. Its totient is φ = 9836064.

The previous prime is 20400377. The next prime is 20400421. The reversal of 20400404 is 40400402.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 13562 + ... + 14990.

It is an arithmetic number, because the mean of its divisors is an integer number (1541540).

Almost surely, 2^20400404 is an apocalyptic number.

It is an amenable number.

20400404 is a deficient number, since it is larger than the sum of its proper divisors (16596556).

20400404 is a wasteful number, since it uses less digits than its factorization.

20400404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1559 (or 1557 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 14.

The square root of 20400404 is about 4516.6806395848. The cubic root of 20400404 is about 273.2412453350.

Adding to 20400404 its reverse (40400402), we get a palindrome (60800806).

The spelling of 20400404 in words is "twenty million, four hundred thousand, four hundred four".