20072581 has 8 divisors (see below), whose sum is σ = 20318144. Its totient is φ = 19828800.

The previous prime is 20072561. The next prime is 20072617. The reversal of 20072581 is 18527002.

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

It is a 6-Lehmer number, since φ(20072581) divides (20072581-1)⁶.

It is a cyclic number.

It is not a de Polignac number, because 20072581 - 2⁹ = 20072069 is a prime.

It is a super-2 number, since 2×20072581² = 805817016003122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20072561) 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, 46141 + ... + 46573.

It is an arithmetic number, because the mean of its divisors is an integer number (2539768).

Almost surely, 2^20072581 is an apocalyptic number.

It is an amenable number.

20072581 is a deficient number, since it is larger than the sum of its proper divisors (245563).

20072581 is a wasteful number, since it uses less digits than its factorization.

20072581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 891.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 20072581 is about 4480.2434085661. The cubic root of 20072581 is about 271.7697238235.

Adding to 20072581 its reverse (18527002), we get a palindrome (38599583).

The spelling of 20072581 in words is "twenty million, seventy-two thousand, five hundred eighty-one".