40720181 has 2 divisors, whose sum is σ = 40720182. Its totient is φ = 40720180.

The previous prime is 40720157. The next prime is 40720187. The reversal of 40720181 is 18102704.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40119556 + 600625 = 6334^2 + 775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40720181 is a prime.

It is a super-2 number, since 2×40720181² = 3316266281345522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40720187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20360090 + 20360091.

It is an arithmetic number, because the mean of its divisors is an integer number (20360091).

Almost surely, 2^40720181 is an apocalyptic number.

It is an amenable number.

40720181 is a deficient number, since it is larger than the sum of its proper divisors (1).

40720181 is an equidigital number, since it uses as much as digits as its factorization.

40720181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 40720181 is about 6381.2366356373. The cubic root of 40720181 is about 344.0354800479.

Adding to 40720181 its reverse (18102704), we get a palindrome (58822885).

The spelling of 40720181 in words is "forty million, seven hundred twenty thousand, one hundred eighty-one".