68144557 has 4 divisors (see below), whose sum is σ = 73386460. Its totient is φ = 62902656.

The previous prime is 68144533. The next prime is 68144567. The reversal of 68144557 is 75544186.

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 6380676 + 61763881 = 2526^2 + 7859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68144557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68144567) 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, 2620932 + ... + 2620957.

It is an arithmetic number, because the mean of its divisors is an integer number (18346615).

Almost surely, 2^68144557 is an apocalyptic number.

It is an amenable number.

68144557 is a deficient number, since it is larger than the sum of its proper divisors (5241903).

68144557 is a wasteful number, since it uses less digits than its factorization.

68144557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5241902.

The product of its digits is 134400, while the sum is 40.

The square root of 68144557 is about 8254.9716534946. The cubic root of 68144557 is about 408.4545367631.

The spelling of 68144557 in words is "sixty-eight million, one hundred forty-four thousand, five hundred fifty-seven".