72181808 has 10 divisors (see below), whose sum is σ = 139852284. Its totient is φ = 36090896.

The previous prime is 72181789. The next prime is 72181819. The reversal of 72181808 is 80818127.

It is a super-2 number, since 2×72181808² = 10420426812297728, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2255666 + ... + 2255697.

Almost surely, 2^72181808 is an apocalyptic number.

It is an amenable number.

72181808 is a deficient number, since it is larger than the sum of its proper divisors (67670476).

72181808 is a wasteful number, since it uses less digits than its factorization.

72181808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4511371 (or 4511365 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 35.

The square root of 72181808 is about 8495.9877589366. The cubic root of 72181808 is about 416.3666331414.

The spelling of 72181808 in words is "seventy-two million, one hundred eighty-one thousand, eight hundred eight".