72041781 has 16 divisors (see below), whose sum is σ = 110336000. Its totient is φ = 40957488.

The previous prime is 72041777. The next prime is 72041807. The reversal of 72041781 is 18714027.

It is not a de Polignac number, because 72041781 - 2² = 72041777 is a prime.

It is a super-2 number, since 2×72041781² = 10380036419303922, 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 (72041731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4441 + ... + 12798.

It is an arithmetic number, because the mean of its divisors is an integer number (6896000).

Almost surely, 2^72041781 is an apocalyptic number.

It is an amenable number.

72041781 is a deficient number, since it is larger than the sum of its proper divisors (38294219).

72041781 is a wasteful number, since it uses less digits than its factorization.

72041781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17448.

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 72041781 is about 8487.7429862125. The cubic root of 72041781 is about 416.0972194039.

The spelling of 72041781 in words is "seventy-two million, forty-one thousand, seven hundred eighty-one".