68918561 has 4 divisors (see below), whose sum is σ = 72972612. Its totient is φ = 64864512.

The previous prime is 68918543. The next prime is 68918569. The reversal of 68918561 is 16581986.

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

It can be written as a sum of positive squares in 2 ways, for example, as 52475536 + 16443025 = 7244^2 + 4055^2 .

It is a cyclic number.

It is not a de Polignac number, because 68918561 - 2¹⁸ = 68656417 is a prime.

It is a super-3 number, since 3×68918561³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68918569) 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, 2027000 + ... + 2027033.

It is an arithmetic number, because the mean of its divisors is an integer number (18243153).

Almost surely, 2^68918561 is an apocalyptic number.

It is an amenable number.

68918561 is a deficient number, since it is larger than the sum of its proper divisors (4054051).

68918561 is a wasteful number, since it uses less digits than its factorization.

68918561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4054050.

The product of its digits is 103680, while the sum is 44.

The square root of 68918561 is about 8301.7203638764. The cubic root of 68918561 is about 409.9951635360.

The spelling of 68918561 in words is "sixty-eight million, nine hundred eighteen thousand, five hundred sixty-one".