20752181 has 4 divisors (see below), whose sum is σ = 20915712. Its totient is φ = 20588652.

The previous prime is 20752169. The next prime is 20752217. The reversal of 20752181 is 18125702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20752181 - 2¹⁴ = 20735797 is a prime.

It is a super-2 number, since 2×20752181² = 861306032513522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20752181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20752481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81575 + ... + 81828.

It is an arithmetic number, because the mean of its divisors is an integer number (5228928).

Almost surely, 2^20752181 is an apocalyptic number.

It is an amenable number.

20752181 is a deficient number, since it is larger than the sum of its proper divisors (163531).

20752181 is a wasteful number, since it uses less digits than its factorization.

20752181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163530.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 20752181 is about 4555.4561791329. The cubic root of 20752181 is about 274.8028603629.

Adding to 20752181 its reverse (18125702), we get a palindrome (38877883).

The spelling of 20752181 in words is "twenty million, seven hundred fifty-two thousand, one hundred eighty-one".