20148181 has 4 divisors (see below), whose sum is σ = 20205612. Its totient is φ = 20090752.

The previous prime is 20148137. The next prime is 20148211. The reversal of 20148181 is 18184102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6421156 + 13727025 = 2534^2 + 3705^2 .

It is a cyclic number.

It is not a de Polignac number, because 20148181 - 2⁷ = 20148053 is a prime.

It is a super-2 number, since 2×20148181² = 811898395217522, 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 (20148131) 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, 28186 + ... + 28891.

It is an arithmetic number, because the mean of its divisors is an integer number (5051403).

Almost surely, 2^20148181 is an apocalyptic number.

It is an amenable number.

20148181 is a deficient number, since it is larger than the sum of its proper divisors (57431).

20148181 is an equidigital number, since it uses as much as digits as its factorization.

20148181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57430.

The product of its (nonzero) digits is 512, while the sum is 25.

The square root of 20148181 is about 4488.6725209131. The cubic root of 20148181 is about 272.1104880210.

The spelling of 20148181 in words is "twenty million, one hundred forty-eight thousand, one hundred eighty-one".