20725881 has 8 divisors (see below), whose sum is σ = 30146784. Its totient is φ = 12561120.

The previous prime is 20725867. The next prime is 20725889. The reversal of 20725881 is 18852702.

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

It is not a de Polignac number, because 20725881 - 2⁷ = 20725753 is a prime.

It is a super-2 number, since 2×20725881² = 859124286452322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 628057 = 20725881 / (2 + 0 + 7 + 2 + 5 + 8 + 8 + 1).

It is not an unprimeable number, because it can be changed into a prime (20725889) 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 7 ways as a sum of consecutive naturals, for example, 313996 + ... + 314061.

It is an arithmetic number, because the mean of its divisors is an integer number (3768348).

Almost surely, 2^20725881 is an apocalyptic number.

It is an amenable number.

20725881 is a deficient number, since it is larger than the sum of its proper divisors (9420903).

20725881 is a wasteful number, since it uses less digits than its factorization.

20725881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628071.

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 20725881 is about 4552.5686156279. The cubic root of 20725881 is about 274.6867220395.

The spelling of 20725881 in words is "twenty million, seven hundred twenty-five thousand, eight hundred eighty-one".