71940181 has 4 divisors (see below), whose sum is σ = 74260864. Its totient is φ = 69619500.

The previous prime is 71940157. The next prime is 71940191. The reversal of 71940181 is 18104917.

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 71940181 - 2⁵ = 71940149 is a prime.

It is a super-2 number, since 2×71940181² = 10350779284625522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 2320651 = 71940181 / (7 + 1 + 9 + 4 + 0 + 1 + 8 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71940101) 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, 1160295 + ... + 1160356.

It is an arithmetic number, because the mean of its divisors is an integer number (18565216).

Almost surely, 2^71940181 is an apocalyptic number.

It is an amenable number.

71940181 is a deficient number, since it is larger than the sum of its proper divisors (2320683).

71940181 is a wasteful number, since it uses less digits than its factorization.

71940181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2320682.

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 71940181 is about 8481.7557734233. The cubic root of 71940181 is about 415.9015210832.

The spelling of 71940181 in words is "seventy-one million, nine hundred forty thousand, one hundred eighty-one".