20431490 has 8 divisors (see below), whose sum is σ = 36776700. Its totient is φ = 8172592.

The previous prime is 20431451. The next prime is 20431547. The reversal of 20431490 is 9413402.

It can be written as a sum of positive squares in 2 ways, for example, as 20349121 + 82369 = 4511^2 + 287^2 .

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

It is a Curzon 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 3 ways as a sum of consecutive naturals, for example, 1021565 + ... + 1021584.

Almost surely, 2^20431490 is an apocalyptic number.

20431490 is a deficient number, since it is larger than the sum of its proper divisors (16345210).

20431490 is a wasteful number, since it uses less digits than its factorization.

20431490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2043156.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 20431490 is about 4520.1205736131. The cubic root of 20431490 is about 273.3799626311.

Adding to 20431490 its reverse (9413402), we get a palindrome (29844892).

The spelling of 20431490 in words is "twenty million, four hundred thirty-one thousand, four hundred ninety".