20475681 has 8 divisors (see below), whose sum is σ = 28488000. Its totient is φ = 13056912.

The previous prime is 20475677. The next prime is 20475683. The reversal of 20475681 is 18657402.

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

It is not a de Polignac number, because 20475681 - 2² = 20475677 is a prime.

It is a super-2 number, since 2×20475681² = 838507024827522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20475683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 148306 + ... + 148443.

It is an arithmetic number, because the mean of its divisors is an integer number (3561000).

Almost surely, 2^20475681 is an apocalyptic number.

It is an amenable number.

20475681 is a deficient number, since it is larger than the sum of its proper divisors (8012319).

20475681 is a wasteful number, since it uses less digits than its factorization.

20475681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296775.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 20475681 is about 4525.0061878411. The cubic root of 20475681 is about 273.5769173398.

The spelling of 20475681 in words is "twenty million, four hundred seventy-five thousand, six hundred eighty-one".