81616670 has 8 divisors (see below), whose sum is σ = 146910024. Its totient is φ = 32646664.

The previous prime is 81616657. The next prime is 81616679. The reversal of 81616670 is 7661618.

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

It is a super-2 number, since 2×81616670² = 13322561643777800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81616670.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81616679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4080824 + ... + 4080843.

It is an arithmetic number, because the mean of its divisors is an integer number (18363753).

Almost surely, 2^81616670 is an apocalyptic number.

81616670 is a deficient number, since it is larger than the sum of its proper divisors (65293354).

81616670 is a wasteful number, since it uses less digits than its factorization.

81616670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8161674.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 81616670 is about 9034.1944853982. The cubic root of 81616670 is about 433.7701112131.

The spelling of 81616670 in words is "eighty-one million, six hundred sixteen thousand, six hundred seventy".