20671520 has 24 divisors (see below), whose sum is σ = 48836844. Its totient is φ = 8268544.

The previous prime is 20671517. The next prime is 20671529. The reversal of 20671520 is 2517602.

It can be written as a sum of positive squares in 2 ways, for example, as 20539024 + 132496 = 4532^2 + 364^2 .

It is a super-2 number, since 2×20671520² = 854623478220800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20671529) by changing a digit.

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, 64439 + ... + 64758.

Almost surely, 2^20671520 is an apocalyptic number.

20671520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20671520 is an abundant number, since it is smaller than the sum of its proper divisors (28165324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20671520 is a wasteful number, since it uses less digits than its factorization.

20671520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129212 (or 129204 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 20671520 is about 4546.5943298253. The cubic root of 20671520 is about 274.4463572029.

The spelling of 20671520 in words is "twenty million, six hundred seventy-one thousand, five hundred twenty".