20431504 has 10 divisors (see below), whose sum is σ = 39586070. Its totient is φ = 10215744.

The previous prime is 20431451. The next prime is 20431547. The reversal of 20431504 is 40513402.

20431504 = 413² + 414² + ... + 508².

It can be written as a sum of positive squares in only one way, i.e., 14899600 + 5531904 = 3860^2 + 2352^2 .

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 as a sum of consecutive naturals, namely, 638469 + ... + 638500.

It is an arithmetic number, because the mean of its divisors is an integer number (3958607).

Almost surely, 2^20431504 is an apocalyptic number.

It is an amenable number.

20431504 is a deficient number, since it is larger than the sum of its proper divisors (19154566).

20431504 is a wasteful number, since it uses less digits than its factorization.

20431504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1276977 (or 1276971 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20431504 is about 4520.1221222440. The cubic root of 20431504 is about 273.3800250726.

Adding to 20431504 its reverse (40513402), we get a palindrome (60944906).

The spelling of 20431504 in words is "twenty million, four hundred thirty-one thousand, five hundred four".