20445531 has 8 divisors (see below), whose sum is σ = 27531024. Its totient is φ = 13495200.

The previous prime is 20445521. The next prime is 20445533. The reversal of 20445531 is 13554402.

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

It is not a de Polignac number, because 20445531 - 2⁵ = 20445499 is a prime.

It is a super-2 number, since 2×20445531² = 836039475743922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20445533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33436 + ... + 34041.

It is an arithmetic number, because the mean of its divisors is an integer number (3441378).

Almost surely, 2^20445531 is an apocalyptic number.

20445531 is a deficient number, since it is larger than the sum of its proper divisors (7085493).

20445531 is a wasteful number, since it uses less digits than its factorization.

20445531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67581.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 20445531 is about 4521.6734733946. The cubic root of 20445531 is about 273.4425726689.

Adding to 20445531 its reverse (13554402), we get a palindrome (33999933).

The spelling of 20445531 in words is "twenty million, four hundred forty-five thousand, five hundred thirty-one".