81624107 has 4 divisors (see below), whose sum is σ = 82164816. Its totient is φ = 81083400.

The previous prime is 81624091. The next prime is 81624113. The reversal of 81624107 is 70142618.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81624107 - 2⁴ = 81624091 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81624107.

It is not an unprimeable number, because it can be changed into a prime (81624197) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 270128 + ... + 270429.

It is an arithmetic number, because the mean of its divisors is an integer number (20541204).

Almost surely, 2^81624107 is an apocalyptic number.

81624107 is a deficient number, since it is larger than the sum of its proper divisors (540709).

81624107 is a wasteful number, since it uses less digits than its factorization.

81624107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540708.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 81624107 is about 9034.6060788504. The cubic root of 81624107 is about 433.7832860148.

The spelling of 81624107 in words is "eighty-one million, six hundred twenty-four thousand, one hundred seven".