72071681 has 8 divisors (see below), whose sum is σ = 79403328. Its totient is φ = 64870000.

The previous prime is 72071677. The next prime is 72071711. The reversal of 72071681 is 18617027.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 72071681 - 2² = 72071677 is a prime.

It is a super-2 number, since 2×72071681² = 10388654404331522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72971681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31325 + ... + 33546.

It is an arithmetic number, because the mean of its divisors is an integer number (9925416).

Almost surely, 2^72071681 is an apocalyptic number.

It is an amenable number.

72071681 is a deficient number, since it is larger than the sum of its proper divisors (7331647).

72071681 is a wasteful number, since it uses less digits than its factorization.

72071681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64983.

The product of its (nonzero) digits is 4704, while the sum is 32.

The square root of 72071681 is about 8489.5041669110. The cubic root of 72071681 is about 416.1547766800.

It can be divided in two parts, 7207 and 1681, that added together give a palindrome (8888).

The spelling of 72071681 in words is "seventy-two million, seventy-one thousand, six hundred eighty-one".