81616156 has 6 divisors (see below), whose sum is σ = 142828280. Its totient is φ = 40808076.

The previous prime is 81616147. The next prime is 81616159. The reversal of 81616156 is 65161618.

It is a super-2 number, since 2×81616156² = 13322393840432672, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81616159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10202016 + ... + 10202023.

Almost surely, 2^81616156 is an apocalyptic number.

It is an amenable number.

81616156 is a deficient number, since it is larger than the sum of its proper divisors (61212124).

81616156 is a wasteful number, since it uses less digits than its factorization.

81616156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20404043 (or 20404041 counting only the distinct ones).

The product of its digits is 8640, while the sum is 34.

The square root of 81616156 is about 9034.1660378809. The cubic root of 81616156 is about 433.7692006217.

The spelling of 81616156 in words is "eighty-one million, six hundred sixteen thousand, one hundred fifty-six".