68099621 has 4 divisors (see below), whose sum is σ = 68476044. Its totient is φ = 67723200.

The previous prime is 68099599. The next prime is 68099623. The reversal of 68099621 is 12699086.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12699086 = 2 ⋅6349543.

It can be written as a sum of positive squares in 2 ways, for example, as 21669025 + 46430596 = 4655^2 + 6814^2 .

It is a cyclic number.

It is not a de Polignac number, because 68099621 - 2⁶ = 68099557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68099623) 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, 187940 + ... + 188301.

It is an arithmetic number, because the mean of its divisors is an integer number (17119011).

Almost surely, 2^68099621 is an apocalyptic number.

It is an amenable number.

68099621 is a deficient number, since it is larger than the sum of its proper divisors (376423).

68099621 is a wasteful number, since it uses less digits than its factorization.

68099621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376422.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 68099621 is about 8252.2494509073. The cubic root of 68099621 is about 408.3647357589.

The spelling of 68099621 in words is "sixty-eight million, ninety-nine thousand, six hundred twenty-one".